In all probability it is something I have done, the only thing is I cannot work out what I have done wrong.
In 2021 I could not get access to my bitcoin in Blockchain so I opened a spectrum account/wallet and tried to import my bitcoin to spectrum which never worked at the time and I tried to use my seed phrase to do this.
I am not sure what I have done wrong here and the only place that my seed phrase was exposed to was my spectrum wallet which at the time I thought I must have been doing wrong, it's only now two years later something seems to have happened, maybe my bitcoin is in spectrum?, all I know is that something happened in spectrum on Friday six times where nothing at all has happened in two years and that is the same night my bitcoin left blockchain.
I am probably wrong here as usual but my seed phrase being in my spectrum wallet I cannot see how that is a problem, from what I have heard it is safer, that is the only time ever I tried to use it.
It's possible the copy of that wallet was infected with malware.
It's possible you have other malware, unrelated to bitcoin and bitcoin wallet, like a keylogger trojan.
I've never used a "spectrum walet". Do you mean that DEX exchange
https://spectrum.fi ?
I'll be honest with you. Online wallets and exchanges aren't a good way to hold coins. You should at the very least have an Electrum wallet for that and learning to use it would be worth every minute spent on it.