dealer changed shoe

Was playing live blackjack and about halfway through the shoe, the dealer just swapped it out for a new one without any real reason I could see. No mention of anything, they just did it between hands and kept going like it was nothing. Threw me off since I track cards for tendencies and try to adjust my bets a bit, so when they do that randomly it just feels off.

Is this normal or has anyone else run into it? I thought usually shoes only get changed at the end or for security issues, not just at random times. Maybe it’s just how the site does it, or was it maybe some kind of mistake? Anyone ever have this happen?