I have an observation with groups that have single planet in it and are shared across multiple platforms.

I see that the 'import from' switches randomly between designated planet and edge. This happens when platform is not on destination planet and when it is on destination planet. Then import from that specific planet becomes cancelled and platform is not picking the import at all.

Could it be caused by this change?
https://github.com/Heniker/factorio-planet-request-group/commit/f086740e331b444aa5512deb85292515e2776d4d

Generally, editing groups per platform should not be done since groups are global.
It would be safe to edit the group once or not flip the group values.

Thanks for reporting this. This happens because I forgot to change group reset logic for single planet case. Really should make a proper testing environment..
Should be fixed in 0.1.8.