Could not load network resources? Too many columns?

My app isn’t working on some devices, clearing cookies now made it say " This site can’t be reached"

I have a lot of columns. Is there anyway to see the load that I’m at to see when/where it breaks?

Ive had this problem in the past but I thought switching them to a big table would fix it.

Please help me find a way for my app to stop crashing and getting buggy at 400+ rows

400+ rows should not be a problem. Can you share a link so we can test?