I am going to guess that the best thing to do is to Run a Factory Reset on your Doorbell.. If there was some issues from the past and having a better Transformer don't cure this my guess is that there is an issue within the camera that needs to be addressed...
Why I say this. Last year I made a mistake and was connecting my Doorbell to random things that it wasn't connected to and while I did blame one of my NVR's I am no longer sure that was the issue however I am more thinking it was when I meant to make a change in one of my cameras that was at 1 time in IP spot that my Doorbell was in. Making the change within IP config. While outside I noticed that the camera every so often kept going on about connection to network.. I went looked at the info and couldn't find anything outside of normal however doing a Factory Reset cured this and the camera has not said that again since outside of the normal times of a reboot or reboot of my router... Doing a Reset should remove camera from SH app, and then remove cover and press hold Reset button until you hear that it is hard Resetting. Then add it back to the app and your network.. My guess is this will cure the issue!?