lberrymage
I was having the same issue with Neo Launcher installed from F-Droid. Just in case the above advice is not clear regarding how to bypass the Restricted Setting, please do the following:
From your phone's Settings go to Apps then pick the app you want to grant Accessibility Access to (in my case Neo-Launcher), then select Permissions, finally at he top right of the screen select the three vertical dot menu. Here you will able to grant the app access to Restricted Settings.