I hav an mth premier csx ac4400 Proto 3. The engine operates fine by itself but will give me trouble when I add other engines to the run at the same time on the same track. If this engine is on the track it won’t allow me to add new engines to the remote to run. Additionally when running in a lash up it will sometimes turn on but not run when given the command but the other engine in the lash up will and the unit will just sit there in neutral. This engine is the common component almost anytime I have an issue running multiple engines in DC. Any suggestions or else I’ll have to bring it in for warranty service? I’ve done a factory reset and still have the same trouble.