I thought of this after a recent bug I found. I use Vivaldi browser and recently it updated. After the update my mouse cursor was not visible when within the browser window. Other programs worked fine. I tried visual studio and steam and epic game store all had my mouse, Vivaldi didn’t.
I closed all instances of Vivaldi via task nanager(was unable to click the x) and restarted it. That fixed the bug and I haven’t been able to replicate so I don’t have anything to submit for a bug report. Just a really strange thing.
What have been your weirdest bugs?


We deployed a client software in a Docker container on Windows 10. It could not connect to the backend, even though we saw SYN packages originating from it.
So, we ran WireShark on the Windows host and saw that the SYN-ACK packages from the backend were arriving there, too, but no ACK came through to complete the TCP handshake.
Eventually, we rolled out a network debugging container on that Windows host and then could see in the tcpdump, that the SYN-ACK packages, which arrived on the Windows host, just did not show up in the container. Hyper-V or something was quietly dropping them.
Other network connections were working fine, just the SYN-ACK from our backend triggered this.