Please forgive the slow response.
[remote "eos"]
url=https://ostree.endlessm.com/staging/demo/eos-amd64
branches=os/eos/amd64/eos3a;
xa.disable=true
collection-id=com.endlessm.Demo.Os
Yep, you’re on the beta channel.
You should be able to switch back to the previous deployment with:
pkexec eos-rollback
However, you may want to try upgrading to 3.8.1 which was released yesterday. If you’re not already on it, try booting to 3.7.8 then running:
pkexec eos-stage-ostree prod
eos-updater-ctl update
This release includes some firmware that was missing from the 3.8.0 release, and has been reported to fix issues on some other Wi-Fi devices too. It would be interesting to know whether it fixes your case. (Your log shows your device uses the nl80211 driver.)