'Read all' button disappearing

[DanShepherd27]

Basically after clicking the 'Read all' button, it starts loading, then opens (probably) the last message, and when I close that, the messages are still unread, but also the button disappears. (neptun.uni-obuda.hu)

[DanShepherd27]

After 4-5 tries, the script deletes some of the selected messages, but not all of them. The disappearing button still occurs (I have to refresh to get it reappeared).

[FeaXR]

Do you have any other scripts running? Which browser do you use?

[DanShepherd27]

Only the npu script and this. I'm using Chrome Version 83.0.4103.97

[FeaXR]

Then I really don't know what could be the problem. I tried it on Chromium based Brave, Chrome, Edge and Firefox and it seems to work fine. Note that I could only test them on the BME Neptun