TestFlight: Expired & removed public testers still occupying the tester slot

3 months before I uploaded a build 1.0(1) and had 10000(not sure why it's showing 10001) public testers via public link. Now this build has expired and I've remove all these public testers, but seems these testers are still occupying the tester slots so that new testers are not able to join test for my new uploaded build 1.0(2), showing "beta is full" to them. I've been waiting for 2 days but those removed testers are still showing in the tester list as "deleted" status and not removed. I've tried upload new builds but it didn't work, what shall I do now?