Tips & Tricks on using LittleFS

Using an old Heltec Lora v2 that comes with an

Im doing everything this guide

And im using arduinojson 7. to save in files of 1 json at a time.
Im not doing any delays or anything to give memory time to save (I dont know if this is necesary).

At some point everything I read becomes NULL and I made sure to open and close all files on each method/functions. I do have format on failure to true, but everything becomes NULL mid-run not at mounting.

Also saw this but I dont know if this is relevant

Suggestions on how to test memory integrity to know when it fails?
Should I use an SD card for this intead of SPI Flash? (w25q64 on HELTEC LORA V2)

Can you share a minimal example project to reproduce the error?