Have you guys tried that solution, seems to work for a bunch of A7 v5 users:
Then from Snapshot you could move to another kind of build if desired, using the upgrade image.
Also, reverting to an old factory image before switching to OpenWrt can help sometimes. Try to flash the oldest factory version found on the TP-Link Website. Archived version of the Website for Archer A7 v5:
Direct download link to the oldest firmware Archer A7 v5 found:
https://static.tp-link.com/2019/201904/20190415/Archer%20A7(US)_V5_190403.zip