If the Tamagotchi is new and you pull the tab out best practice is to still press the reset button. I’ve never personally noticed this issue but I haven’t ran a V4 is many years now.
I haven’t ran my V4 is a while now but O have never noticed an issue on my versions. Have you tried resetting it? You will lose your character and progress by resetting it but it might fix any glitches that occure. A lot of glitches tend to appear when you don’t reset the Tamagotchi and just...
Have you thought about trying any of the newer versions? The coloured screen ones have many features although they’re in Japanese, the P’s can be patched into English. The ID L E comes in English but is very expensive and hard to get nowadays.
There’s a guide (here) on what each icon does and gives you a bit more information about it. It might be worth a read and will further help with any questions you might have.
The Tamagotchi V4 is known to have many glitches. If you use the search function on TamaTalk you can find many posts about it :)
As for debugging, I don’t see how it would fix glitches but a guide on how to do it can be found here. Just to note, only US/North American versions (connections)...
I’m pretty sure the Digimon did have a relaunch a few months (years?) ago. Finger crossed the connections would be relaunched though, so many memories.
My first vintage that I bought myself was a Morino that I bought 5 years ago, although my first vintage I had was passed down from my Mum to my Aunt, and then to me. It's a yellow P2 (Orange) Japanese version :P
This tends to happen a lot with the older vintage ones. It's like the buttons decrease over time. Was it bought NIP or previously used? I've found the the NIP buttons tend to be 'harder' and easier to use.
I tend to put the battery in, and then press the reset button and they always seem to work then. I'd also recommend cleaning the insides too, dirt can build up over time.