Unfortunately we don't have a known work around for this particular unlocked device. But I think you are probably right in your guess it is at least in part to do with the fact it is an unlocked phone.
I'm sorry I don't have a better solution to offer.
I am also in touch with OnePlus. This is not related to an unlocked
bootloader. The issue also occurred on a brand new OnePlus 6 device that
was fully stock. Here is their most recent response to me:
Based on your MMS concern, this is definitely related to the carrier as the
Multimedia Messaging Service feature on the OnePlus devices are already
compliant to its standard services. Some carriers may need to update such
settings on their end in order of it to function accordingly or if it needs
to be activated to work in a specific access point. This is mainly based on
carrier support but we'll definitely take note of this so that it will be
looked into in the future.
So, they are saying that the issue is carrier-related and not phone/OS
related. Is it possible to pass this issue to a technical team for them to
look at? Oneplus is selling more and more devices in the US and I would
think that this would be a big issue for their users on T-Mobile.
Thanks for getting back with us. Wi-Fi calling on non T-Mobile phones is tricky because the manufactures say it should work but since we never sold the device, we did not have the chance to verify and tweak the software to work with our Wi-Fi calling service. It is possible that some aspects of Wi-Fi calling will function but we cannot guarantee the full functionality of non T-Mobile devices.
I have a new Oneplus 6 and everything worked out fine. Just switched out the sim card.
Have you tested sending an MMS message in a location where do you not have
mobile data (somewhere with a very weak or no signal, or by turning off
mobile data but leaving wifi on)?
No. Not yet. Just got my phone on Monday. Still tweaking the settings.
I just turned my airplane mode on and kept wifi on and was able to call my cell phone from my office phone and texted my folks and received a text back. So its working here in Minnesota. I'm having other issues like on my past weekend trip to door county going across Wisconsin I lost data midway to greenbay basically, yet got data in greenbay and once heading up the doorcounty peninsula away from Greenbay lost service for the rest of the weekend. Yet my Wife's Iphone 7 had service here and there. I believe it is due to my settings here: BYOD T-Mobile data & APN settings
This is what it is suppose to be:
- APN Protocol: IPv4/IPv6
- APN roaming protocol: IPv4/IPv6 or IPv4 only when roaming internationally
Mine are set at this:
- APN Protocol: IPv6
- APN roaming protocol: IPv4
Plan right now is to modify my settings to match the recommended. The IPv4 seems to be the one that might be causing me some trouble, at least the way I'm thinking about it.
I have no problem with WiFi calling or WiFi SMS. The issue is only with MMS
(that is, sending photos/video/group chats via text), which do not seem to
go through the VoWiFi connection, even when VoWiFi calling and SMS is
I saw the news that the OnePlus 6T will be T-Mobile certified, so maybe
this issue will be addressed when that happens, and the fix pushed out to
older devices as well, as it almost certainly appears to be a software
issue with OxygenOS.
On Wed, Aug 22, 2018 at 12:38 PM kartboarder22g <firstname.lastname@example.org>
Oh ok, I suppose I can try that too to see if I have an issue with that, I will say I had an HTC one m8 as my last phone and I basically took my sim card out of that phone and threw it into my one plus 6. Why that matters is I just got back from a trip to Norway and wifi was my main use of communication in Norway, using the HTC. When I was copied on photo text messsages from my Wife the photos never came through to my device. So again, I'm thinking maybe my settings I posted above might have carried over on the Sim and they are allowing this either way I'll do a quick check and find out.
Alright I just went airplane mode again, and turned on wifi, then sent a photo text to my Wife asked for a reply that she got it and she responded yes she got the photo. Everything seems to be working smoothly here, if I understood what you were asking. Again need to mess around with my phone to avoid roaming as I think again it is APv4 that is giving me issues, I hope.
OK, do me a favor and try one more thing. Because sometimes I can get it to
work when I go on airplane mode and re-enable wifi manually (this sort of
forces it to use wifi since the mobile connection is inactive). Where I
have trouble is where I have a very weak mobile data signal (such as in my
house). VoWifi is working and enabled, but it seems to be giving priority
to the mobile data signal (which is so weak it cannot be effectively used)
instead of the wifi connection. If I move to the other side of the house
that gets a stronger cell signal, the MMS will go through.
So, if you have a location where you have a very weak signal, can you try
again with mobile data ON?
It seems to me that the issue is that, with MMS, if mobile data is on, it
will always try to send via mobile data regardless of your VoWifi settings
(even if "VoWifi preferred" is enabled).
On Wed, Aug 22, 2018 at 1:24 PM kartboarder22g <email@example.com>
Yes I can try, but I only know two places where I tend to have cell issues and those are my Mother-inlaws house and my folks house. Granted though, I had bad reception in those areas with my HTC One M8. So, I have many more bands on the One Plus 6 so I don't know how it will behave at these locations I have mentioned. Plus I don't go to these locations too often, so it will be a while before I can get you a response. I will try if I happen to stumble along the situation. If it works for you, it may be airplane mode is your only option when sending those types of texts. In Android 4.0 on my HTC I know you could configure the mobile data to be used when wifi was weaker, or maybe it was the other way. I know I played with this idea, but found that it would tend to jump to mobile data too easily, really wanted it so when I leave my house or work which both have wifi, it would allow my google maps to update via mobile data as the wifi signal was pretty weak or going out as I was backing out of my garage/driveway and google maps was trying to update data yet the phone was trying to do it through a weakening wifi connection. Don't think they have this option anymore though in Android 6....don't really blame them though as I want to save mobile data as much as possible.