Update that to the absolute latest: https://microg.org/fdroid/repo/com.google.android.gms-9452273.apk
Self-Check the device launching microG Settings. All options should be checked.
If that doesn’t work, then it’s some imcompatibility with the P-GO app itself.
Also, I read somewhere they’ll ban users with rooted phones.
There’s an updated Pokemon GO thread already on the forum: