MKRNB1500 and SerialSARA

Hello

I'm trying to understand how to use the SerialSARA to read and write commands to u-blox manual.

I'm using the SerialSARA passthrough example as a guide. However, this sample reads/writes the ublox one char at a time and uses loop() calling function to apparantly reset the internal serial buffer.

When I try to write my own version of the code where I can get result and parse it, I can't read anymore chars once I read 64 bytes.

With that said, I can not find documentation or the source of SerialSARA.

Any pointers is appreciated. If it helps to loook at code, here is a public gist of what I've been testing/working with: https://gist.github.com/netskink/b2bcce6c6f08e832cb955bd1762822f6