Sometimes our email providers 'automatically' mark/reject emails from groups.io
because they -think- it is spam. When that happens somehow groups.io knows it
happened and they mark your user for "having a problem" (or even remove you
from the group).
Go back and make sure you have the correct "status" on a group by group
basis (by using the online interface to groups). Especially check your "email
delivery options" to make sure they are right.