Hi, and welcome to the forum.
Can I ask why you are deleting via opt+ (file manager).
To delet a programme I just go to ‘media’, select the programme to be deleted, press ‘OK’ scroll down to delete and hit OK. Done.
Sorry just noticed you said “even” using opt+, from this I gather the above method doesn’t work either. Just tried mine and can delete using either way.
Have you tried removing the batteries from the remote for a while, could also be they are running low and need replacing. Good luck.