Okay so this is a weird issue but hear me out. I own an LG G4 and as usual, the play store updates itself to stay on the latest version. But I noticed the original play store that came on the phone is faster, not laggy, and the UI just looks better. Is there a way I can keep the phone ON that older version? Every time I downgrade it, it just updates soon after.
Unless you block Download Manager, Google Play Services and Google Pay Store from accessing internet, then you can't stop it from updating. Blocking them will also have the effect of preventing other apps to update which I presume you don't want.