Questions regarding Tamagotchi version 6, 4 & 4.5

Question regarding the Tamagotchi version 6 (Music Star)-

I just wanted to confirm that, is every model of Tamagotchi of this version got the unresponsive button problem ?

Questions regarding the Tamagotchi version 4 & 4.5-

Does the version 4.5 of the Tamagotchi is having more items and games than the version 4 one without removing any items, characters that's available in the version 4 one?

Also, I remembered someone did said that the Tamagotchi v4.5 have 20 more characters than the version 4 one but when I checked both of their character chart, I counted and realized both of them have the same amount of characters. 52. How come? Is it just because the person lied?

Extra question regarding the Tamagotchi-

Does the newer Tamagotchi versions include all items and characters from the previous Tamagotchi versions?

Example: Tamagotchi Version 5, includes all the items and characters from the previous version of the Tamagotchi and add ins some new one. So does the next version of the Tamagotchi, includes all the items plus characters from the Tamagotchi version 5 and add in some new ones.

Sorry for bad English and please help me with these things that I'm wondering for an answer Thanks.

As far as I know, all v6 have laggy, unresponsive button.

I make things a little easier by pushing down "close to the top of the buttons".

It currently works for both of my v6Stars.

~Phnx