I originally filed some Form 510s earlier in 2021 for 2020 pass-throughs.

I read the Maryland admin release and realize I need to file the 511.  Before I file the form 511, do I have to amend the 510s with all zeros?  Can I do the 510 amended via e-file?  My system is telling me not to file

the 511s.  What is the best way to proceed?  Thanks for your help.  The Maryland (revised) deadline is rapidly approaching!

Signed, 

Confused & frustrated