Alright, found a weird glitch. Placed a high rise residential type-2 building, then I selected the tile that was hidden behind that and clicked delete tile. I have no idea if it worked, but my resource income changed, so something happened, at least. Anyway, after deleting that tile, it seemed to select the tile to its upper-left. Don't know what that's about, and it's not an issue, but the issue happened when I then clicked the tile to the upper-right of the high rise and clicked delete, instead of deleting the tile, it replaced it with this glitched version of the residential high rise. The glitchy version looks like the regular version but with the upper 1/4 of the building cut off. I can't seem to select the tile its on anymore.
Okay, fixed it. Turns out I could select the tile, but it would highlight the empty space where the top of the high rise should have been. Also deleted the original high rise to find that another glitchy version of it was on the unseen tile I deleted. Loading back shows it has the same properties of the other glitchy building, in that selecting it highlights around where the top of the high rise would've been. I'm gonna do some experiments to try to replicate this and hopefully find the issue.
Update: Okay, messed around a bit and I managed to do it again with another building, this time the regular high rise residential rather than type 2. Don't know how, and I don't really feel like experimenting more to figure it out. I think the game just doesn't work well with tall buildings. Anyway, I'll send you a message with the save file and let you figure it out if you want. If not, just ignore or delete the message.
By the way, this was all in the latest version 2.7 from start to finish.
Suggestions:
You should probably make selected tiles drawn over other or something, but I'm not a dev, so I don't know how hard that would be, if it would cause other problems, or if there's a better option.
The tutorial guy says to click the alloy refinery, but since that's the only building whose information won't show up when you hover your mouse over it, some might get confused and think, "does it mean the metalworks?". Might want to say to "click the alloy refinery (top right building option) to continue".