[bug] strange optics and behaviour of the start/stop button of the export queue

while mass export in jxl is the system slow, ok, and it is difficult to stop the queue. Sometimes it stops sometimes not, the button looks strange ... this is after clicking to "0"

<img width="1920" height="1080" alt="Image" src="https://github.com/user-attachments/assets/b302d810-4989-4c15-9062-9ddc54d54c3a" />