I want to very politely ask someone (my professor) not to do something anymore, and I've been searching about how I should do it for more than 2 two hours, yet I could not find any useful answer.
To give you more context, I have a timing issue with one of my classes at university, and my professor is working on the issue. However, I want to ask him not to work on it anymore and tell him I'll figure something out myself, but I don't want it to sound rude or sarcastic. How could I ask him? Are any of the following options appropriate?
1 - I kindly ask you not to work on this issue anymore.
2 - Please don't devote your time to working on this issue anymore.
3 - I just wanted to respectfully/politely ask you not to work on this issue anymore.
4 - I'd be grateful if you'd stop working on this issue. (I think it's not appropriate to say "stop doing that", though. To me, it sounds like I'm annoyed and I'm asking him to stop annoying me, but I'm not a native speaker of English, so I'm not sure.)
More generally, how can I ask someone not to do something without being rude/sarcastic or without implying that I'm annoyed?