Tried 2.0 on my Macbook Pro. Set it up as a new core. Decided to switch back to 1.8 which was still set up on Mac Mini 6,1. Roon works fine. Ios legacy remotes work fine, but can’t get remote app to run on Macbook. (Same machine that ran 2.0 briefly.) Downloaded 1.8 legacy all-in-one but get message
“this version is not compatible with your database”.
When you installed Roon 2.0 it would have updated your Roon Database to the current 2.0 schema … which is not compatible with the 1.8 version.
Thus, after re-installing 1.8 you also need to restore a Roon Database backup that was made when you were running 1.8.
Or alternatively stick with 2.0 or start from scratch.
UPDATE
I’ve just read you post again and think your issue is installing 1.8 as a remote (not core) … in which case just delete the Roon and the Roon DB folders from that machine and then reinstall 1.8.
Checkout Roon Lab’s help site for details on DB location.