Bug in SIM manifests as bug in FONA library

[jwallis]

I do not believe there is a workaround Adafruit can implement, but hopefully people will search here and find this issue. It is about reading SMSs from the SIM module and character sets.

Short version:
1.SIM7000A firmware version B03. This probably also happens with SIM808 and possibly SIM53xx
2.send a SMS with "aaaa" to your FONA
3.send a SMS with "a{aa" to your FONA
4.write a short program that does a readSMS(0); and readSMS(1); and you will see that the readSMS(1) returns the wrong string. There will be an extra '\r' at the end.

Long version:
https://forum.arduino.cc/index.php?topic=660925.0