painting over it will accomplish nothing. for the moment until it's resolved you should be using vinegar to clean it off - google to find out specifics like if it's white vinegar you need.

do an online 311 complaint and do it every single day the mold is present.

do you have a window or fan in your bathroom ? open window / turn on fan.

this link lists tenant/legal orgs which offer free legal advice - call one or two orgs, let them know the situation and ask what your options are.

ask about compensation, and viability of withholding rent until this is permanently fixed -

https://www.reddit.com/r/AskNYC/comments/nx1hks/how_does_rent_assistance_work/

do not withhold rent except under legal advice.

after you've spoken to an org or two, notify landlord via letter with signature requirement what needs to be done etc - tell the unofficial "super" that you're not going to settle for it being painted over.

good luck.