As mentioned above not a sign of a problem, in fact pretty darn common.
You can live with it (doesn't really effect the reloadability of the brass unless the dent is a deep crease).
Or, you can usually tune that dent out (or mostly out anyhow) with a combination of extractor tuning, gas flow tuning, buffer weights and/or buffer spring force. (where are your ejected brass ending up in relation to the gun orientation?). Where your brass ends up (clocking wise) can tell you a lot about how your gun is gassing & ejecting.
Personally I usually tune it out on my range guns as I don't like dented brass but don't usually tune it out on my defense guns as I like those to run no matter the dirt, ammo, heat, lack of lube, etc.