Certain WA users are unable to join my self-assignable subscriber groups. They receive an error stating "There are no more slots!" but I'm only at 20 used out of 100. In addition, the person receiving the error is already part of other subscriber groups, so joining more wouldn't affect slots available anyways.   This first came up in January 2024. Mochi joined 4 hidden groups as part of a scavenger hunt, but got the "no more slots" error upon trying to join the fifth and final one. I manually added them to the group without issue. Others have been able to self-assign the same groups since, also without issue.   Now I'm using entirely new groups and Mochi is still having the same problem while others are not. It seems to be an issue with the account trying to join the groups rather than the World/groups themselves, but I can't verify.