Doorbell ringing analog chime randomly

Hello all, I wonder if someone can help me. I have a Ring Doorbell 3 pro that was battery powered. I took the advice of a neighbour to use the 2 wire power supply for our old analog doorbell (I say old, it’s a new build so only 4 years since it was fitted) to power the doorbell so I don’t need to keep changing batteries. This has been working fine and the doorbell is wired in on the back and the App shows that Solar status is connected. The issue I had is that the analog bell box chimed twice in the middle of the night a few nights ago with no rhyme or reason. I sealed the wires on the back to prevent moisture as suspected that this might just be bridging the connection. Last night, after 3/4 nights of now issue, the it did the same, sometimes just a single press (a ding rather than a ding and a dong, If you understand 🙈) What am I missing? What could cause this? What could I do to stop the bell box ringing and keep the doorbell charging. Thanks in advance for any help. N.B - the old bell box chime isn’t digital, it’s definitely analog