Mines and C4 dont despawn after going off, this issue has been around for a while but since last update its really bad, in big fights you see them littering the battlefield everywhere. My guess is that this also impacts performance. Besides that still no answers or resolution to the major lag spikes that been around for over a month now discussed here https://forums.daybreakgames.com/ps...etworking-and-the-may-5th-maintenance.256599/
Mines and c4 despawn issues will be fixed in the next update. Your other topic is being looked into. Thanks for your report!