Hi all, I found out both the problem and the solution! With the unexpected extra time at home due to "social-distance" from people, I spent some time being "extra-close" to my tractor.
I re-viewed the loader manual again, noticed it says in the manual (in one very small line and sentence) that if the hydraulic fluid gets contaminates in it it can cause the valves to become sticky. Well I changed my fluid again yesterday and viola - the sticky valve situation went away immediately!! It's not all that hard to do it just takes a fair bit of time to get done and I'm usually wanting to do a project other than spend my weekend working on maintenance.
I do not know how the fluid could have become contaminated other than through wear and time. But, it had been just 300 hours since the last fluid change. That's what the maintenance schedule calls for and my records show that I changed it at 650 hours - I'm now at almost 900 so I'm calling it my 900 hour change. I'm at 859 so it was 200 hrs on system before it got sticky.
Upon writing this I realize that between the last change and now is when I added my diverter vale into my system. That consisted of adding a couple of hoses and switching around two others and while it temporarily open up the system I'm positive no contaminates got in. I used new hoses, new fittings, etc., etc., and I was extra careful whenever I had an open line. I used air pressure to blow out my new hoses before install also. I don't know for sure what might have happened - but now it seems to be cleared up, and due to new fluid in the system. So a $70.00 bucket of oil, $20 or 30 dollar filter and several hours of my time and back to the races! The oil I got at Napa, the filters are Donaldsons that I had ordered and had on the shelf.
At any rate I just wanted to post my resolution/solution to my problem, and let any others know that sticky valves "just might" be fixed by changing the fluid.
Happy Tractorin' to all. Greg