Strange Behavior in GA4

I am at a loss as to why my traffic seems to suddenly drop of a cliff. We have made no changes to our GTM tags, GA4 events, and have been using SEMrush diligently to find and correct errors within our site - but as you can see in the image below, since July 1 we've encountered two periods where I traffic seems to inexplicably drop for a long stretch of time, then climbs back up.

Does anyone know what can cause this, or what I can check to find out why this is happening?