I have a Heltec V2.1 running FW 1.2.49.
The Android app shows an available upgrade to 1.2.50.
When I run the upgrade it says successful however the unit continues to display upgrading forcing me to reset.
Then the unit still shows FW 1.2.49.
I have run the same upgrade on the TTGO V2.1-1.6 and it does work and upgrade to 1.2.50 successfully.