Have any of you experienced indications that indicated trans problems that are caused by the NSBU but actually turned out to be the ignition switch?

Mine acted up today. Trans feels like it's stuck in tow/haul and lock up is very quick in lower gears. Took it to a friend who pulled the codes and it came up with "sudden loss of power or connection." He cleared the codes but it didn't fix. Drove to work and now the pass/lock is illuminated. He suggested an ign switch, too.

I have read some posts about the ignition switch but in most instances as I recall it was not the problem.

I have gotten a couple hard downshifts in the lower gears when stopping since I replace the NSBU. My son thinks it is possibly the internal trans filter or a valve body issue. My truck has 264K and the trans was always flushed vs replacing the internal filter. I towed a lot when I was in the transport business so maybe it needs changing. I am going to try that and see where I go from here.