For context, I recently installed a new CPU (Ryzen 7 5800X) and motherboard into my machine, and concurrently had to Reset Windows for an unrelated issue. After the reset, I had to reinstall all my adobe products. My CPU and RAM is overclocked, however I don't experience any issues in any other programs and the behaviour of this issue would suggest to me that it's not related as it only affects Lightroom.
Since reinstalling Lightroom, I've found that the app will simply close without warning while performing a publishing to Flickr action, (very occasionally but less often while exporting in batch as well). There's no error dialog or crash notification, it just spontaneously closes to desktop. This wasn't a behaviour I ever experienced before. Sometimes the publish action hangs quite a while without doing anything as well after a random amount of progress. I just tried to replicate now and it crashed to desktop almost as soon as I pressed the publish button.