m-8 destroyer also doesnt want to fire

grinding down and rebuildign them seams to have fixed it for me, try if it helps you also

I have tested with all 4 and it seems that only the swarmer is functioning currently, the other three fail to shoot at all no matter what, freshly placed ammo everything.

did you lock onto a tagret with the lockon button before firing?

I've been having the same problem, I'm pretty sure the new patch broke something within weaponcore because other weaponcore mods are having similar issues. Could be wrong though.

The Defense Shields mod added controls to shift power around to various shield facings, which use the NumPad keys, including NumPad0. This is blocking the lock action key.
After editing the WeaponCore config file at C:\Users\<User>\AppData\Roaming\SpaceEngineers\Storage\CoreSystemsClient.cfg (path may vary) and changing NumPad0 to another key (I used X), missile locking and firing started working again for me.

you can also change the button form ingame with the command "/wc remap"

press NumPad0 for unlock the weapon and lock target with mouse scroll

You can find the solution in the weapon core manual, in Controls/Targeting

https://psteamcommunity.yuanyoumao.com/sharedfiles/filedetails/?id=1989583682

to change the lock the default key is numpad 0

idk if this will help people but it helped when i had cameras set up