Upgraded Board from 2.2 to 2.4 ... many issues

Correct. Your new board shipped with Grbl 1.1 which CM3 doesn’t support.

You should be able to use a newer (nightly?) build of UGS which supports Grbl 1.1.

If you wish to use CM3 revert to Grbl 0.9: GRBL 1.1 and Carbide Motion 4