So I was just playing my private world on 1.17rc1, the usual, I got some wither heads and I went to make the wither underground, I make it in a very small 1 by 2 area, and it doesn't work, so I assume it's because of the blocks, so make adjustments, yatyatyatyata, later I realize there must be a 1.17 glitch and I have to wait until the full release (I may still have to) but then I tried it in a creative world, works perfectly, I went into my world again, tried the same way I did in my creative world, doesn't work, I think it may be because of my world glitching, I made in at 1.17pre1, maybe even snapshot 21w08, but my point is, my world can't spawn a wither, I tried bringing my friend in with Opened Lan, he got creative, but even he couldn't do it, if you could possibly fix this in the full 1.17 release, that would be very appreciated, but if you could also find a way to find my world, it's called, Bruthor #2? I think, but 1.17 ss. (that whole thing is the name, from Bruthor to ss, and my Minecraft name is PurpledNicked. Thanks, EDIT: Yall cant understand, if you read this,  you would know I did it underground.