I still can't rearm mine at stations only can synth.
I think I found how it works.
I just found the issue, and possible workaround. I just got pair of them to OC G5, and did bunch of testing, as no one else than myself cant really test it properly (it seems, given lack of input about it)
First ever try it was shoot once, then come back to rearm, and it didnt rearmed (that was few days ago when unlocked them), since it mag was not full, but at 6.
Today decided to give it another go, since information about it rather minimal, and besides, If not myself tested how it works, then I could be not sure anyways.
It seemed whenever ammo in mag is not at 9, then it might not reload(rearm), but once reloaded to 9, it does rearm, every time. So if ammo is fully depleted, synth once is required, to be able to rearm it - so if ammo reserves are getting low, do not empty last mag, otherwise synth will be required. But again, long as mag is at its full at 9 then it will rearm.
Seems like there is issue whenever magazine is not full or not, rather position of cmdr or other things (like system, station, sever lag, modification used etc.) Further testing will be done, and will reply here about what I learn from it.
How's no one else could figure out that is only magazine issue, is beyond me. But there it is, and until fix came out, thats how the "workaround" works.
Also they seem to not properly load always having a 7 or 8 ammo count in a mag and when it reloads it automatically shoots a few shots.
This happens after re-loading game. Even before quiting game, if mag was at 9, after reloggin back it can be less than that, for some reason, and no idea what it causes it.
I just had 8 after relog into game, so yeah... the remain one shot from 3-burst shot was shot after reload by itself, on its own.
Try Autoloader, it actually makes weapon be able shoot 4 times instead of 3, so it adds one extra burst per reload, and it fixes also issue with mag, since it ensures mag reloading itself at all times whenever hardpoints are deployed. So works both for rearm issue and respawn issue when mag is less than 9, so weapon does not fire on its "own".
Still, quite broken it is, seriously limits what can be used at it right now... Basically autoloader is a must, just to have usable workaround to even using those cannons. Fdev wth.