I had a very similar problem with similar behavior on my 100Watt. After much experimentation, it was necessary to replace the magnetic limit switches. In my machine it was a little bit of a pain, because I had to thread the cable through the articulating cable management system. Just take pictures, follow the wires on the old one, and put everything from the new one in the same spots. You can buy them on Amazon.

The switch I needed is the one in the link below. Not sure if yours will be the same.

https://www.amazon.com/gp/product/B071HR3CCT/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1