Sorry for the delay in responding everyone. My dad was rushed to the hospital and is currently in the ICU. The tractor got pushed back a bit.Perhaps start out simple. Crawl under the tractor, remove the connector going into the solenoid valve assembly, inspect and clean if necessary and reconnect. Also, as @whitetiger suggested, inspect the wiring harness for any damage. A solenoid is a relatively simple device and it's out of the weather inside the solenoid valve body so maybe less likely to be the problem, but if you don't hear/feel it moving when current is applied it's most likely bad.
You can see where the solenoid valve assembly is located in the image below. You should at least be able to get to the connector without removing the left rear wheel and body parts/panels.
View attachment 101012
Thank you for all you input. I plan to get back out there this week and start working on the pto issue. Again, thank you all and I’ll update soon.