Really weird thing happened when I entered my Cardano Daedalus wallet seed string into a multi-currency wallet: I saw my bitcoin balance! Please help me understand this weirdness

I have a few hundred dollars worth of Cardano that I bought many years ago, this is stored on the Cardano Daedalus wallet, under the old 12-word seed string. I only have Cardano (ADA) in this Daedalus wallet, because that is the only cryptocurrency Daedalus stores.

I want to move my Cardano coins to the Atomic multi-currency wallet that I currently use; Atomic supports Cardano. But could not get into my Cardano Daedalus wallet, because it does not seem to run on my computer (there seems to be some technical issues with Daedalus).

Now I read that all wallet seed strings are universally compatible with other wallets, so I had the idea of downloading another wallet which supports Cardano (the Exodus wallet), and entering my Daedalus wallet seed string into Exodus, with the hope of being able to see my Cardano balance in Exodus.

So I did this, but when I open this Exodus wallet using my Daedalus seed string, I saw no Cardano, but instead saw in the exact bitcoin balance that I have in my Atomic wallet!

I have a few hundred dollars worth of bitcoin in Atomic, and this precise balance I was able to see in the Exodus wallet, after setting up Exodus from scratch, using my Daedalus seed string!

Now this totally confuses me, because this Daedalus seed string has nothing to do with my Atomic wallet.

So how did my bitcoins become associated with my Daedalus wallet seed string?

I’d really like to understand what happened, because it seems very weird.

(Note that in the end I was able to access and transfer my Cardano by entering my Daedalus seed string into the online Cardano wallet at https://adalite.io , and I then saw the correct Cardano balance in AdaLite, and was able to transfer my Cardano to Atomic).