OK, I was having some issues with my HOTAS vibration too so today I decided to completely reinstall DCS, I removed my previous DCS install (which shouldn't have been a problem since it was the openbeta, which is a different directory, but I still wiped it), I also deleted my saved games\dcs.openbeta directory. I reinstalled DCS WITHOUT any plugins/addons (no tacview, no SRS, not buttshaker software) and absolutely no mods (the only things I copied from my previous installation was the input directory and the campaigns progress). With this clean installation I tried again, same result, nothing happens after "send it".
I'm happy to help debugging this issue, I'm just not sure if DCS provides any debugging/logging tools. I can go for a desktop sharing session too if you want.