As pointed out by another poster - its unlikely they were using the stock Android text message app like you or I might. More likely using a proprietary messaging app - that might not have worked properly once the Samsung update was applied. Very common for OS updates to break apps.
No. It’s. Not. Not anymore do updates break commercial apps. IT’s extremely rare.
ONLY if the app is a first-party app (written by the Bureau or their contractor) would a Samsung update have a CHANCE of breaking the app. The industry is beyond that now, and besides, an app issue does not affect previously transmitted data.
IT’s all a distraction, a red herring. The data ARE there. PERIOD.
I’d rather believe that they deliberately deleted the texts if you regard the dates in question.