You were completely right, I was running out of heap space, thank you!
Solution to this is quite straightforward though: create many smaller arrays and send/free them one by one, instead of a larger one

Hello! I am filling a cJSON Array with AddNumberToObject() function. At first it works fine, but at some point the add_item_to_object() function within AddNumberToObject() begins to return NULL, thus not writing the number and producing afterwards the error "LoadProhibited", when dereferencing the n...

Ok!, thx for your quick reply

Hi, I am working on a project with ESP32 where I read 16-bit data from an IMU sensor in deep-sleep, hence with ULP. In order to downsize the data stored in RTC_SLOW_MEM region I would like to save 2 16-bit measurements in one 32-bit register (r0,r1,r2,r3), though I don't know if this is possible. An...