I've had a problem with my Galaxy Watch4, which started 3 days ago.
Bluetooth had been turned off temporarily on my phone and so my watch lost connection (which is fine), the issue that occurs is when I turn Bluetooth back on it can no longer connect.
Sometimes the device disappears from my Galaxy Wear app and I have to perform a reset of the watch to connect it again as if it's a new device. I've done a reset about 5-6 times already.
Sitting in the galaxy wear app and pressing connect it will just refuse to make the connection.
My phone will connect fine with the watch, up and until the first time Bluetooth is turned off on the phone. If I turn off Bluetooth on the watch, then turn it back on, my watch reconnects fine.
Other Bluetooth devices such as my Galaxy Buds2 will work and connect fine without issue.
Clearing data and cache for galaxy wear app, and the galaxy Watch4 manager plugin. Reinstalled both of those. Tried resetting my network settings on my phone completely. Resetting the watch and reconnecting a number of times.
Model number : SM-R870
Phone is a Google Pixel 4a running Android version 13