I won't defend his wider performance because I didn't watch the full match, but just looking at some of the highlights there are a few occasions of "comical defending" being pointed out which are really just Maguire not being able to mark two players at once. With Jaidon Anthony's shot, for example, Maguire didn't do a huge amount wrong; Solanke's backheel pass was firstly very well executed and secondly Wan-Bissaka was caught out of position due to it being a quick transition. Equally, for Billing's first header, Maguire has both Billing and Solanke in the area and is the only player positioned to challenge either of them. (He should've done better on Solanke's subsequent header though)
I don't think he merits a place in the side, to be clear, but some people are ludicrously harsh on Maguire at times.