Thanks for all the input. I think Tony has it right, it definitely needs a cleaning. With the spool off and it spinning fine, I just kept spinning it for a few minutes until I felt no resistance. Even though I had done that unsuccessfully before, when I did it for a few minutes straight it felt smoother and when I replaced the spool it felt ok without locking. I added a couple of drops of oil to the port and it felt really good. It did fine on the next trip out that was brief due to storms, but it brought it a 16 in brown with no issues. The next trip out, things were going great until I caught a trout and as I was reaching for it over some grass/dirt/mud, the hook came out and lodged in my shirt. I went for the trout first to get it back in the water and set my rod down on a dry spot, but in my Three Stooges like fumbling to get the trout and release it unharmed, I got the line and rod twisted around me and the reel ended up back in the water. Although it didn't get as bad or completely lock up, there was immediate resistance when cranking the reel. It pretty much constantly feels like there is sand in it. I forgot to mention that the first time it happened I had also just dropped the reel into the water.
I searched for some Youtube videos. The Ci4+ specific ones either had no audio or the one that did was in a foreign language. I need to hear what and why I am doing each step. There was a very good one on a different Shimano reel, and if I kind of combine both videos I'm feeling confident enough to give it a go. I'll be in Pittsburgh for a couple of days next week and worst case is I bring them a bag of parts and my tail between my legs, lol.
And I do have a couple of backup lower end Shimano reels but they all have issues like the bail occasionally not turning over and slightly lower gear ratios that are annoying enough that using the gritty Ci4+ is about equal. Using the backups really gave me even more appreciation for a Ci4+.
Now if only someone could fix the absolutely horrible May spinner fishing. By far the worst I have had in 9 years. Sections that reliably produced 30-60 trout for the last few years have had me struggling to get to even 10 or 15 fish. I'm pretty sure it's the water temps since I couldn't even find one above 50 until just this last week.