I know this is fault of McMyAdmin but idk what are chance that they fix this:

So McMyAdmin put "Prefix, Suffix and Default" outside "Options" and reload config, so that means it loses prefix,suffix until server restart. After server restart PEX automatically put "Prefix ,Suffix and Default" under "Options" is there possibilty to make it preffix and suffix compatible that they don't have to be under Options or when you do /pex reload it automatically put it under Options so there is no need for server restart.

Best regards.

PhonicUK (dev of MCMA) is generally pretty responsive to issues (and knows where to get a hold of me if he has any questions about PEX), so if you brought this up with him he'd most likely be able to fix things. However, first you should make sure you or your server host have got the latest version of MCMA, since he might've already fixed things and you/your server host just are on an older version.

Thanks for fast answer, i did contact about this on their forums. But this is obvious old bug on mcmyadmin because there is guy with same problem in 2014...

https://bukkit.org/threads/permissoinsex-prefixs-breaks-upon-mcmyadmin-modifications.286905/

#1897

And ofcourse i'm using lastest mcma version.

And there we go with answer from MCMA support:
Permissions exporting is no longer being maintained. We recommend that users that need to edit permissions from the web interface upgrade to MCMA3 to use it's web-based file editor.

So they wont fix small bug...

Ok, then you should update to MCMA3 -- that seems to be where the development is going.