In my case there were no fireworks.
I had over 20 incoming links, a cool-down and a multihack.
So your case fits to installed mod being the cause, good.
I had this problem today on several portals and made videos. None of the portals had activity on them like flips, fireworks, or beacons. They were all blue and fully deployed when the BB was attempted. In some cases when it was attempted there was an SBUL in place and in other cases they weren't. I ended up Jarvising manually and moving to another hub to attempt each time. Eventually one worked so I ran a set of fields using that portal.