Not necessarily if they are permanently connected in parallel.
It’s definitely not advisable to do, but I can’t see why it’s inherently wrong.
There are a number of factors to take into consideration if you choose to do it and if you don’t already know what those considerations are, I’d recommend not venturing there.
In the interest of keeping things educational, our lord and saviour @Battery_Mooch headed an excellent conversation here —> Here’s what can happen when you parallel (mix) different cells in a pack