Anyone listening?

I don't always reply to new bugs since I don't always have something to say

In this case since other games work, which they didn't before, this is a bit lower priority for me to look into this release, which is already way overdue.

Tested with 0.10-7003-c0b0b6b00. MGBA changed behaviour with commit 0865b89, with Sonic Advance 2 never stopping the transfer of data, rather than stopping but not connecting.

Checked what purports to be commit d9627e. Restored original behaviour of wanting to download the program, but failing synchronization. Did not fix all issues. Is it working on your end?
Attached another report.
Report2.zip

It definitely is working on my end, I checked multiple times. I was using the US version, not the EU version, but the US version was failing before too.

I also have the US version, and have verified it fails as well.

Doing a reset of all settings to see if that helps.

Reset of settings made the game worked once, and never again.I don't know what this is, but this is certainly not fixed.

You appear to be correct, it's still broken for me sometimes.

Upon inspection, as best as I can tell all the right data is being exchanged, but then there's a race condition between the two GBAs because they change comm types a few times. This is a known issue in mGBA and isn't going to be addressed for a bit.