Ubisoft are aware of the issue https://forums.ubisoft.com/showthread.php/2317891-The-division-2-update-1-30-PS5-problem?p=15338284&viewfull=1#post15338284
This is also in BC mode. Still a poor showing, but thats Ubisoft :P
This isn't a native port?
It would explain the drastic difference in load times. IIRC, most BC games running on a Series X have been noted to have faster load times than PS4 BC games running on PS5.