Whenever I enter or exit a building or someone's house, there is this pause (?). For example, you don't enter and exist smoothly, but everything just kind of pauses and freezes for a few seconds and then the game starts running again. Can someone help me with this? Is it because of my mods?
I'm on mobile and sometimes it crashes when entering a building or transitioning areas after hanging as you describe, occasionally with some stuttering movement first, so I think it's just a bug. Might wanna submit to the support forum. For me it's been rare enough I've just ignored it even though it's sometimes lost me some fairly significant game-time. Seems to always happen when I'm on top of my game holding where I want to go, so I think it's trying to put the player on a tile offscreen during the transition that hasn't been loaded yet. Something like that, I dunno.
It could be mod related. For example if you use Seasonal Villager Outfits (especially as part of a large mod list and/or with an older computer) there will be some delay on switching locations. Some changes are being made for SMAPI for the next major release to help with that.