Okay so I had an idea pop in my head and it worked
As seems to always be the case, it was my antivirus blocking stuff in a weird manner. Even though for some odd reason disabling it entirely didn't work, my work around I've used in the past seems to have done it and the connections went through. Thanks for all the help though, and sorry for putting you guys through this headache.
And for the future, make sure to have anybody using Kaspersky Antivirus to go through the Firewall application settings, find both Java/OpenJDK and the .jar file in question, and turn on the "Do not scan all traffic" setting in the exclusions tab.