I know it seems redundant, but perhaps disabling it, clearing Tasker from memory, then opening Tasker again and enabling it again like doing so for first time, could clear things...... Otherwise, I suspect your Android Version could be out of date or device not playing nice with Tasker's accessibility check. I'm not sure about that, though.
Such issues as you're describing are ---- approximately ---- commonplace. I've seen them on various devices over the years with same and different Android versions. You can try to troubleshoot, and it might go away temporarily, but can come back randomly.
Due to accessibility features being very potential security risks for malicious apps, sometimes (or routinely) the system won't register and needs to be "bumped" so the accessibility turns on..... or as seems in your case, the features seem to be on but it still asks.
On my MacOS computer, my third party mouse software ALWAYS tells me "do you see this window when you boot computer, if so, hit FIX" and I cannot disable that, but I never ever see the window. I don't have the problem I need to fix, and there is not a way to shut it off. It's important enough for some not to see the boot message that the message is always supplied when opening the app in my preferences, even though the problem does not exist and never has.
VERY regularly on most recent Android versions, it tells me every week or so "do you need to check the accessibility services for ## apps?" or something like that, but it's always on like it should be, so such a message is redundant, but that's computers for you!