Can't add members to group, even if there are free seats!?

Currently we are on a free plan on SaaS with three members and we can’'t add two more members to the group. Yes, we’ve checked usage quota to catch other members in subgroups (none found). See attached pictures. We don’t know what we are doing wrong.

We will upgrade to professional plan at the beginning of 2025.

What can we do?

Nevermind. The “Restricted access (beta)” in group settings was enabled, disabling it let us invite more members.