Ok sounds highly likely they are preparing to swarm. The best solution is to split your hive before this happens, you can’t really prevent it - at this stage they are committed.
As they are capped time is of the essence.
Zip over to a bee supply shop and buy an empty Nuc box (base/lid/box, or the plastic ones). When it stops raining move 3 frames into the nuc: 1 capped honey, 2 brood which must include the swarm cells, and add 1 empty wired wax foundation frame (also from bee shop).
You must be careful to leave the queen in the box without the swarm cells.
In a few weeks you will have the flow hive plus a nuc with laying queen. If you don’t want a 2nd hive you can easily sell it on Facebook or probably here for $200 - $250. There’s a few beekeeping groups like Backyard Beekeeping Australia that are quite active for this, or FB marketplace, gumtree, etc.
Here’s a description of the process in more detail How to make a swarm-control split - Honey Bee Suite
Most important thing is to act asap because you’ll loose half your bees and a bunch of your honey if they swarm.