S7 Edge WiFi calling and WiFi battery drain bugs

- Member Since: Nov 4, 2015
Model: SM-G935T
Android version: 6.0.1
Basedband version: G935TUVU2APD7
Build number: MMB29M.G935TUVU2APD7
Bug #1 - S7 Edge WiFI Battery drain bug
S7 Edge
- On LTE radio only battery drain is about 0.3% to 0.7% per hour with no active use of the phone.
- On turning on WiFi battery drain goes to 10% to 11% per hour with no active use of the phone.
- On turning on Airplane mode to shut down LTE, followed by turning on WiFi, usage is still 10% to 11% per hour
This has been tested on two S7 Edges and both phones seem to have the same issue. "Keep WiFi on during sleep" feature is set to Never to reduce battery usage.
Samsung S6 SM-G920T on Android Marshmallow comes in at around 5% to 6% per hour when on WiFi. Why is it that the S7 Edge with a bigger battery is burning more than twice the battery on WiFi? The S7 Edge phones go from 100% to 0% in about 550 to 580 minutes pretty reliably with zero active use and WiFi on.
Bug #2 - S7 Edge WiFi calling shuts down WiFi.
WiFi calling is turned on. Turning on airplane mode, followed by turning on WiFi so LTE radio is off, but WiFi is on. WiFi calling registers and you are able to make calls. WiFi stays up. Then when you make a call using WiFi calling, the call rings and connects, then about 10 to 40 seconds later, the WiFi is automatically turned off and the call drops. After a delay of about a few seconds (between 3 to 5 seconds), WiFi is automatically turned on again and connects to WiFi Access Point. WiFi calling registers again with the IMS system and phone indicates WiFi calling is ready. As long as you don't make calls, the WiFi connection remains up. When you make a call and the call connects, the WiFi automatically turned off after about 10 to 40 seconds, causing a disconnect and WiFi is again turned on again after a small 3 to 5 seconds delay.
When the phone is removed from Airplane mode so that LTE radio is turned on, WiFi is also turned on and WiFi calling registers with the IMS server. At this point when a call is made, the call is connected over WiFi calling and the call continues with no issues.
Samsung S6 SM-G920T on Android Marshmallow has no such WiFi issues with the same test setup.
This behavior is repeatable on two S7 Edge phones multiple times, across 5 different WiFi AP vendors and types and signal levels.
What is the procedure to raise a bug report with T-Mobile and Samsung? I'm very surprised that TMO and Samnsung both missed this during QC.