This issue has been fixed in firmware branch os33:
https://github.com/OpenSprinkler/OpenSprinkler-Firmware/commit/cc0b0887ef1c4d2f1ef3386120b824c9fe71de47
we will release it in soon. This only happens on arm64, and does not happen on any other platform. It’s due to arm64 implemented ultoa function differently than other platforms.