Switching jobs in Belgium while work permit expires

Hello All,

I have this very specific situation,

My current single permit expires on 31st of March 23. My current employer has already filled an extension application. However, I have found a new job now in Dec 22.

My new potential employer is asking for a resignation letter from current employer with end date of 31st of March 23 and then they can start the new single permit process. They want to start my new contract from 1st May 23 due to the permit lead time.

My questions are:

- In case my employer agrees for a longer notice period and allows resignation for 31st of March 23. Will I keep my rights of residence in Belgium while my new single permit will be in process however, old would have expired already?

Will it be counted as a gap during my Nationality application? My stay in Belgium will be legal till I get the new permit?

- In case my employer only allows me the standard notice period of 7 weeks. Then I will have leave around end of Jan 23. Then there will be a 3-4 months gap before I start my new job. Then how long can I stay in Belgium without a work permit while another will be in process? Will I lose my rights of residence and will it affect nationality application in future?

- Any other ideas solutions are highly appreciated.

Also, I am married to an EU citizen, should I go for a F card to deal with my situation?

Thanks upfront for your kind help. I am really in urgent need of help and advice. Thank you so much all!