Creativity is better face to face.
WFH works perfectly for routine non random event related work.
When you need to communicate fast, need to come up with insights - essentially when you need that high bandwidth node to node interaction of working together - then face to face is significantly superior.
We are designed to work with other humans - chunks of grey matter exist only to interpret non verbal cues. Heck we actually suck at symbol manipulation and math, those are learned skills we force our species to pick up.
It should not be surprising that when working face to face, we end up using those default programs installed in us to get more work done.
Just being able to clarify something is faster if done in person because you have access to body language, eye direction, and tone.
Video goes only so far, and is still not as immediate and in person as physical presence.
https://interactions.acm.org/archive/view/march-april-2014/h...
https://www.theatlantic.com/magazine/archive/2017/11/when-wo...
And now that they are at home, they are not trying as hard to pretend they are listening closely, and since they are more comfortable, they are staying in the meetings and saying what they want? Whereas before they would let the most assertive person talk, and after a few minutes could not tolerate the in person meeting anymore and so pretended that they were all in agreement so you would let them go, knowing they would work out the actual details amongst themselves later?
And now they don't have the option of working things out after the meeting, which is another reason the meetings are taking longer.
The biggest issue for you is probably that you have a lot of wasted time where only a part of the team is working together in the meeting but other people who are not involved in that part are just waiting for them to finish.
Do some research on the tools that engineers use to work asynchronously and train your product team. Also consider smaller video chat meetings, and chat rooms, etc.