If you feel that you're having trouble recovering, I would suggest tracking your recovery metrics while you're at it. Hours of daily sleep, litres of water intake, daily macros, and if you're taking supplements a nice checklist to make sure you've remembered to take them. Sleep, diet, and hydration play a huge role in your performance in the gym.
In terms of experimenting, everything needs to be done over a long period of time. I'm thinking months and years over days and weeks. If you want to switch to the same volume but fewer days, that's a great idea, but try doing it for 3-4 months. When you're tracking your workout, make note of things like the RPE of sets, your fatigue levels (e.g. motivation and soreness), and you can make yourself some graphs for reference.
If in 4 months you see improvement, rest is better, lifts are improving, body composition is changing up nicely, then I'd continue doing what you're doing. I don't think it's necessary to double-back to 6 days a week. 12-15 sets per muscle group per week should be sufficient, assuming you're hitting RPE 8/9s, even if it's only 3 days per week.