AFAIK webcore/smartthings can’t pickup external notifications. I had similar setup/hiccup before. I synced the status via tasker by picking up notifications and then relaying it to smartthings via sharptools plugin.
Tuya switch name = A
corresponding smartthings virtual switch = VA
tuya switch A physically turned on - tuya sends notification " switch A on" - tasker picks up this notification - tasker makes sharptools turn on virtual switch (VA) in smartthings - virtual switch (VA) turned on in smartthings
Smarthings VA turned on – tuya tap to run( turn on switch A) activated via webcore/ST – tuya switch A turned on
above example will cause a loop, as turning on the virtual switch in ST will trigger the tap-to-run( turn on switch A) in tasker. But it will stop there as tuya switch A is already turned on and therefore tuya wont send another notification.
Alternatively you can try another app called MPP suite in playstore and another app available via MPP Suite website( Tuya4AM). MPP suite has ST integration and its own rules etc to sync devices.
But all the above options cost few dollars( tasker/sharptools/tasker plugins/MPP suite). I tried tasker method, but now I am using MPP suite method. Everythings works like a breeze.
Please let me know if you need help in setting any of the options listed above.