Maybe? That's why we usually declare vars as _x or _y instead of just x and y unless we literally want to deal with the calling instance's position. Still feels unlikely, but as long as you got moving forward it really isn't important.
Viewing post in Converting TDMC to use Tiles comments
I'm having this exact issue. This works perfect with the test square and it really is pixel perfect. However it prevents my player object from moving at all.
*editing because jump still works, but im sticking into walls and on floors. Last night I played with the player object mask and got it working with a detailed tileset, but switched to a simpler 32x16 block tileset today and this started happening.
Just so I understand, the collision handling code you had previously that used place_meeting worked fine, but when you swapped to tile_meeting it started behaving badly?
This will be a difficult issue to resolve in this thread. I would recommend joining the Game Maker Community Discord Server and asking there. Most members are familiar with my system and could help you trouble shoot, and if I'm available, I'll help personally. Here's an invite.
https://discord.gg/gamemaker