Warping! Others have hit on a lot of this, so I’ll try to be brief.

• warping is due to the plastic shrinking as it cools. This builds tension in the lower layers of the print
• bigger prints are naturally more warp prone
• part shape and aspect ratio also plays a role. Parts with big aspect ratios (eg much wider or longer than the other axis) are more warp prone. Parts with sharp transitions are also more likely to warp
• different filaments are more warp prone than others. PLA is least prone, followed by PETG. ASA/ABD are the most warp prone I’ve printed so far
• fiddling with temps and speeds can help
• make sure you have good bed adhesion (clean bed, good first layer, etc)
• having good bed adhesion will only take you so far. I’ve had prints pull my magnetic bed plate up
• you can try printing a draft shield around your part (think a skirt as tall as your part)
• IMO eclosures are the way to go for warp prone parts. You’ll need to be somewhat careful about chamber temps getting too high (this can cause nozzle clogs for PLA/PETG) or not getting high enough (ASA/ABS will still warp in a cool chamber). My enclosure has a removable lid that I pop for PLA/PETG and has insulation/bedfans/a filter for ASA/ABS