If we're going to be honest, many people in the crypto world have problems with their crypto wallets/accounts sometimes showing $0, whether it's because some hacker emptied their wallet on CEX, or the same thing happens to them in a non-custodial wallet.
Also, the balance may show $0 if the wallet is not synchronized, if we entered the wrong seed or if we chose the wrong derivation path. With all that, "crypto" works 24/7/365, except in the case when you can't access your CEX, you don't have internet or you forget your pass to the non-custodial wallet.
I would just conclude that not everything is as it seems, although we may think that everything is great in the crypto world.