Wow !! My friend, this is a more difficult problem than it sounds. First, the problem must be located, for this you have to do a couple of basic tests, once the problem is located, the difficult part comes, modifying the circuit to eliminate it, this is difficult because the manufacturer never reveals its electrical diagrams and the user (you in this case) must have basic knowledge of measurements and welding. I have seen similar incompatibility issues on other equipment such as treadmills. I don't dare to assure you that this project can be carried out remotely, but we can do something: you send me a detailed description of the problem and the documentation that you have, I'll tell you the tests you have to carry out and you do them, the process would be trial and error. Do not assign me the project or pay me milestone, only if we can solve the problem you do it, I will trust in your word.
In the worst case, we must redesign the electronic circuit but this is complicated because I must know each component that I must handle, power consumption, which parts I could reuse, etc.
I am a Telecommunications and Electronics Engineer.
Best regards