Get used to it.
From the perspective of running several consulting/job-shop types of business, this happens all the time from clients/customers/prospects (who are effectively employers, and are in very analogous positions here).
We'll be going along through the process of sales, project definition, quoting, etc, and then all of a sudden they just go silent. No reason, no explanation, just ghosted. For days, weeks or months.
Then, suddenly, with no warning or explanation, they call/email again, and the process picks up as if not a day has passed -- the only difference is often they are in a bigger rush and want the project more. (seen similar with VCs too)
So what happened? Almost anything. Other business have their own priorities, and their own fires to put out, and can often quickly get distracted from a project.
The difference is one of perspective. For us the employee or service provider, this job is a critical priority. For them, it's one of many, even for top priority projects.
It's just not the same sense of urgency from different sides of the table. I've learned (after way too much anxiety) to just accept and ignore it -- mostly.
And the times I couldn't just ignore it and felt that I had to do something, and only barely managed to hold myself back? Almost always glad I played it cool (even if I wasn't cool inside my head).
YMMV