That sounds more of a planning / culture issue than something thats unavoidable. At the beginning of the pandemic, this happended alot, where I had to wait for PM input or what have you, but eventually, culture molded to be more async and we were given more trust to do things we felt were right.

We re-structured meetings to be more productive, for example: PMs are required to write all the requirements in advance of a refinement session so everyone can read them first, and you are expected to have read them. This opens up for async discussion (via Jira messages) and come refinement meetings, a way to ask and discuss directly.

In the last 2 years since thats taken place, I have not had another instance of waiting on a PM for a response.

In cases where we need something more urgent, there are always ways to get a PM on the line ASAP, we have protocols for that (seldom used, but they exist)