[hvalentim]

In case it helps I am attaching logs I got of serial communication between weewx and weatherduino using interceptty,

I tried downgrading Weewx from 3.1 to 3.0.1 so as to match the version you are using with no luck.

As far as Cumulus is concerned, it seems to be working as before.

Note: the attached log files include the results of "wee_config_device" and "service weewx start" threefold:
1) the command line issued and results seen;
2) what showed up in syslog;
3) what data was effectively exchanged through serial comm.