As other people have said, oozing. In addition to their fixes I would suggest looking into sequential printing as a print method to be aware of. Rather than printing two objects layer-by-layer, sequential printing will complete all the layers of one object before starting on the next. This has the major benefit that you get zero oozing or stringing between parts. This can be a lifesaver on materials like PETG that will always string to some extent. The only gotcha is that you have to place the parts further apart on the print bed, as the extruder will collide with any nearby completed parts (Prusa slicer has all of this built in, including alerting you if any collisions would occur). I don’t recommend it for every print, but it’s a useful tool to have in your toolbox.
Matrix is an open source protocol for federated chatrooms, kind of like if someone mixed Lemmy with Discord and Signal. You make an account with a Matrix ‘homeserver’ (can be your own self-hosted server) just like Lemmy, so you’ll have a username like user@homeserver.com. Once you do you can join any number of Spaces, akin to Discord servers. Unlike Discord, these servers will be hosted on the homeserver which means they can be self-hosted, and often come with strong safety guarantees like end-to-end encryption or the double ratchet algorithm as seen in Signal (depending on how the homeserver is configured). Matrix is really just a protocol, so there are a bunch of chat clients that implement it, the first-party client is called Element, but there are many to choose from.
I would argue the main reason to use Matrix over Slack or Discord is much the same reason you’d use Signal over Whatsapp - data privacy. Because you can self-host the homeserver any spaces you make can be hosted on your local machine. For those who are privacy advocates that’s a very good reason to use Matrix over most other solutions. If you’re a company or a concerned individual that routinely deals with data that really shouldn’t be on the ‘cloud’ (e.g. trade secrets, materials under NDA, personal information, etc.) then Matrix seems like a better fit than say Slack, provided you self-host. Discord has been under fire for their privacy policy for end users, so you might consider Matrix as a replacement for Discord too.