warning buzzer(?) when entering car to start

On rare occasion, (only 3 times in my 8K miles of ownership) I have heard a strange buzzer noise when I first open the driver door prior to starting the car. Is it warning me that something with the car is not right? I have searched forums and the manual and can't find anything about this. Has anybody else experienced this? Can anybody verify what it would be? It sounds like a warning buzzer of some sort, not a chime or horn honk.

When I heard the buzz noise yesterday, I started the car and drove without issue for about an hour. I received a message about needing to "service the tpms" near the end of my trip. Was it coincidence, or was the buzzer sound I heard before starting the car warning me about a potential issue? When I heard the buzz one other time, it was shortly after that that my remote was not able to be detected. Coincidence?

Now for a separate question: when a tire has a flat and it is repaired, does the tpms need to be recalibrated? The left rear tire had a flat a week ago, and a NTB shop fixed it for me. The manager said that he didn't have the updated tool to correctly reset the tpms, but after the repair was made, the sensor initially seemed to be working fine. However, yesterday (a week or so after the tire repair) the sensor failed and that is when I received the error message. The fact that it was working makes me think that it did not need resetting; but now it doesn't work, so I'm wondering if they damaged the sensor. I didn't spray any goop into the tire when it had the leak, so I know that it wasn't damaged that way.

Any thoughts about either the buzzer or my tire issue?