are you sure you have actually received any transactions?
this is just my guess but maybe that 0.203 bitcoin that you saw was an unconfirmed transaction that was double spent later on so you never actually received it. or maybe the private key you imported is already compromised and you did receive it but then it was spent by the other person(s) who have the key.
try using a block explorer to verify that the addresses in your wallet actually have a balance.
I checked all address and non of them has coins in it. In the last 24 hours i didn't received and spent anything.
In this case the first or second scenario more possibly?
you say things that don't exactly make any sense. for example:
We talking about the ChipMixer now, i used them many times. Highly trusted, i believe they didn't used my keys. After the private keys was imported to my wallet, i deleted the session.
how can a service like ChipMixer use your keys? you don't give them your keys. they are stored on your computer inside your wallet!
and what do you mean by "session" that you deleted?
and did you use a block explorer to check your balance?
Edit: in my transaction history shows no incoming nor outgoing transaction in the last 24 hours.
this is why i said check a block explorer (https://[Suspicious link removed]/en/btc/address/) so that you can be sure if there is anything there or not.
How my private keys can be compromised? The only third party i trusted, who gives the mixed coins as private keys is Chipmixer.
My session deleted with the chipmixer, otherwise i can get back my private keys and import again.
In my mind, it's looks like Electrum bug, the private keys was imported to the watch only wallet, and after the shutdown wasn't saved. It worked always, hundreds of times.