It looks like the culprit is in the simpletext library's _safe_gets function. The hardware echo feature that's useful for the terminal with half duplex serial ends up causing trouble for other device communication. Before removing or making hardware echo a configurable feature, existing serial and fdserial apps will need to be tested. This would also have to be coordinated with a blocklyprop terminal update.
Below is a block comment that I would recommend adding. Alternately, it could be something that only gets executed when rxPin == 31 and txPin == 30, and maybe some mode conditions.
It looks like the culprit is in the simpletext library's _safe_gets function. The hardware echo feature that's useful for the terminal with half duplex serial ends up causing trouble for other device communication. Before removing or making hardware echo a configurable feature, existing serial and fdserial apps will need to be tested. This would also have to be coordinated with a blocklyprop terminal update.
Below is a block comment that I would recommend adding. Alternately, it could be something that only gets executed when rxPin == 31 and txPin == 30, and maybe some mode conditions.
Here is some test code that fails with the existing library, and executes correctly when the echo code is commented out.