Is a week of no contact normal after returning from training?

My situation is a little different because it’s not just that he hasn’t replied… my messages aren’t delivering at all.

He’s active-duty Army and recently returned to his home station after being away for training for a few months. The last thing he told me was that they were heading back and that he was hoping to get a day or two to rest before going back to regular work.
It’s now been about 7 days since I last heard from him.

My messages have stayed on one check, and I also tried other messaging, but those aren’t showing as delivered either.

I completely understand that post-training recovery etc can get hectic, and I’m not expecting constant communication. I’m mostly wondering whether a full week with the phone seemingly completely offline/unreachable can still happen during this period, or if there are sometimes unexpected last-minute duties, exercises, restrictions, or other things that can suddenly come up and keep someone completely off-grid for several days.

I’m still pretty new to how military schedules work, so I’d really appreciate hearing from anyone who’s experienced something similar.