Could some of your problems be with the film?
When I did develop color with C-41 I got my best results, at least that’s what I liked, with about a 10% over development. The negatives produced prints with more vibrant colors. For each gig I made sure to use film from the same batch getting more consistent results. I used a stainless steel tank and put it into a bowl of water to maintain temp through the developing process.
Now all I do is Ilford XP 2 Plus with C-41. I use Arista chemicals from Freestyle.
All my color is digital now. Your issues just reassured me I made the correct choice.
Where in L.A. do you live? My daughter and her family live in LaCanada. Decades ago, serving in the military, I had an apartment in Long Beach for about 7 months, my last stop before separation from active duty.
I make photographs as a return ticket to a moment otherwise gone.