CobianSoft

I've noticed that the tasklist becomes unresponsive for a few seconds whenever you click "OK" after editing a task if there are above a certain number of tasks. I'm not sure of the exact amount, but I noticed it immediately after importing my old task list from Cobian Backup 11 Gravity with 25 tasks. I tried completely uninstalling and reinstalling the program, including deleting all config files manually, and the issue persisted.

It is very reproducible, simply create any task and clone it enough times until the task list slows down when clicking "OK" after editing any task. Cobian Backup 11 Gravity does not have this issue and stays responsive.

Just disable Options-Visuals-Show sizes in the task list

That does improve responsiveness, however if you repeat the same process rather than being unresponsive if you click another task quickly enough it switches back to the last task you had selected. It still feels sluggish compared to the older cobian backup. I hope this can be improved in future versions.

Yes, for large tasks this can take some time. The changes need to go back to the engine and they must be received again.