Hi Ante,
Do you have an overview page to check the status of your queued tasks? It could be that one of your scheduled event tasks is stuck and needs to be stopped / removed. Hopefully that helps. Please let me know if you need any further help.
See also documentation about how scheduled events work with task queues: https://docs.mendix.com/refguide9/scheduled-events-task-queue/
Have a look at this page https://docs.mendix.com/developerportal/deploy/environments-details-redesign/#model-options where enabling scheduled events is discussed.