Yes, i tried version 2.30.0 (directly from docker hub) and behaviour is exact the same. Under 1000 messages i cannot do/see anything, after hitting 1000 messages for queue i can work with them, HOWEVER it looks that i can work only with messages that are over this 1000 mark.
So i have 1004 messages in queue? i can see only last four of them in browse queue. I try Operations -> removeAllMessages(), i got 4 as response and just last four are removed and first 1000 are still in queue, but cannot see/work with them