Those leaves look like they show some ph issues. Iv had the same problems before and a little now. If you water with 6.0 and runoff is 6.5 the soil ph is probably over 6.5-7.0. Just my opinion And I’m no master.
I now check my ph in 3 ways probably overkill.
1. I have 2 different meters that I calibrate everytime.
2. I use the indicator liquid to check color.
3. I use ph strips also.
I dont trust my ability to check color of the indicator, I definitely dont trust the meters, so thats why I do the different methods.
I also give my water about 15 minutes to settle out after ph correction before testing again.