Starting yesterday, every time I would join/host a match, my key inputs would get stuck. I'd end up continually walking in one direction, holding shield, spamming an attack, etc. If I press the key again, it stops, but it continually happens. My opponents don't seem to have any issues and it doesn't look like a desync. I haven't had this issue before, but now it happens with every match. Not moving in the waiting room doesn't change anything, nor does pressing alt. High latency mode doesn't work period. Offline mode works just fine.

I'm running the browser based version on a Chromebook if that helps.

Any thoughts on this?

I am having the same issue. My internet is very good also so that is not the issue.

That's definitely a new one. Have you tried messing with quality settings?

I've tried switching between hardware and software, which changed nothing. I usually keep it on hardware and low settings. Suggestions and things I've tried include:

Pressing alt
Having no other tabs open
Not moving in the waiting room
Only using the mouse to select things
Changing settings

Nothing has made a noticeable difference. I'm wondering if the issue is only restricted to the browser based version. Like I mentioned earlier, this started happening out of the blue - I didn't have any issues for several months. While I appreciate the chance to practice my techskill against the CPU, I'd like to play against real people again too.

Updating, for anyone else who may be having the same issues.

I managed to fix the laggy inputs by adjusting my Flash settings. I had to go into the Peer Assisted Network panel, remove the website from there along with all stored data, and then start from scratch and re-enter my settings. My inputs no longer stick.

Unfortunately, this seems to have caused another issue. Half the time when I try to either create a room or join a room, Shockwave Flash crashes. If I reload it, it repeats the same issue over and over. I've found that if I repeat the above steps and erase all data, I'm able to join/host rooms again, but it inevitably crashes again a few matches later.

I think this is more of a Chromebook/Flash issue, but I haven't been able to find much information on anything. I'll update again when I have more information.