I tried using the webrepl on my pyboard-D but it doesn't go further than entering my password. After that, nothing happens. Not even the repl output gets sent to the webrepl. Sending/Receiving files also doesn't work.
When I interrupt my uasyncio program or any other executed code on the pyboard, everything works fine again. (But I need to Interrupt from the console, it doesn't work through the webrepl)
Oddly enough, starting the same code again from the webrepl makes the repl output appear in the webrepl, however the KeyboardInterrupt still won't work.
I don't have these problems on my esp8266 or esp32.

I'm using micropython 1.15 nightly from the download page.

additionally: Sending files to the pyboard through webrepl doesn't make them appear in the PYBFLASH drive on windows until a hard reset. Not even a soft reset makes them show up. But that is a separate issue and not really important (who uses webrepl to upload files while connected to a pc...)

Steps to reproduce:

1. Connect to wlan and start webrepl
2. Have a script (or run from serial repl) start some code:

import time
c=0
while True:
    print(c)
    c+=1
    time.sleep(1)

3. Connect through webrepl
4. Entering password works, serial repl prints connection established

Expected Behaviour:
The output of the script gets printed to both serial repl and webrepl, file upload/downloads work while the script runs, KeyboardInterrupts work.

Actual Behaviour:

1. No output printed to the webrepl. Interestingly though, if you Interrupt the script from the serial repl and start it again from the webrepl, the output gets printed to the webrepl. But reconnecting the webrepl results in the same problem, no output.
2. No KeyboardInterrupt. Not even when the script prints the output to the webrepl.
3. Webrepl is only responsive while no script is running (so you need to interrupt it from the serial repl before you can enter anything in the webrepl).
4. No file upload/download while a script is running.
5. Disconnect only due to timeout while a script is running.