Thank you for reaching out!
Could you describe to me the issues you're having? Are only certain ports affected? What kind of SFP -> RJ45 adapters are you using? Does the problem disappear when SFP modules are unplugged?
As for port mirroring, TSW200 has a separate logic for SFP connections, so this should not be an issue. However, TSW200 only supports standard SFP, not SFP+, so I'd recommend checking what technology the adapter uses.
Another aspect that could be causing the issue could be incompatible PoE devices. TSW200 only supports active PoE (802.3af/at) at 30W max per port and 240W max total power budget.
Await your response.