hello, the old bitcoin-qt wallet... it is a bug or a break manip ? please !?

[theHelpbitcoin]

Hello, I describe my wallet:

HDwallet
old from 2013 and 2019
bitcoin core has synchronized with the blockchain and is synchronized,
I have no passphrases!
I modified the DBcache… around 3000 instead of 550 MB!

I tried to import my wallet, but it doesn't work, it doesn't show the bitcoins!
someone helped me the last time, but now I'm stuck.. no way to find my old wallet with its keys and addresses has worked!
I searched the forums but nothing helped me!
the last time I succeeded but there were no real bitcoin exchangers… strictly speaking, against state currencies.

Hello I describe my problem:

and the problem is simple: I did a simple manipulation: create a new wallet and add an address to my new wallet,
to change the wallet.dat file that was stagnating there!

Since then I have not seen these btc which are on these new wallets and these new bitcoin addresses where they must be!

[theHelpbitcoin]

And I changed the file type,

For example :
a wallet.dat, which I had, was modified by software ... (it doesn't matter the software since the wallets are still there!)

Software has modified the file,
changing from .dat to .axx, and from .axx to .dat, after removing the software!

and going through .dat to .txt to read it too!