We are not onsite, from the sounds of it, you have had part changers out not troubleshooters.
Need to find a troubleshooting technician that will verify what is going on and provide the proper repair, not just change parts and cross his fingers.
Might try to find a recommended Trane dealer to have a look. Or see if there is a contractor from this site that is close to you on the contractor map.
Issues may have been caused by the prior tech not using the proper parts as required or just has thrown parts not needed.