I hope we don't have to wait another 28 days to determine if your issue is solved, again, then
You need to clarify a few things... a Wemos D1 R2 board IS an Arduino UNO compatible board (at 3.3v)... so is that the only board you are using, or are you also connecting a regular UNO to it??? and if so... how and why?
What hardware sensor are you using to detect this current from the external circuit, and are you also controlling that circuit with a relay or is it totally independent?
Timely details will help this process along. Thank you.