The TL-WN823N only support 2.4G. You can check in its spec, on the Frequency part: http://uk.tp-link.com/products/details/cat-11_TL-WN823N.html#specifications

As shown on the attachment, the IP in the address bar is 192.168.88.1, probably the web browser redirected you to that address when you type in 192.168.0.1. The Mikrotik should be the admin page of...

You may check whether this link helps: http://www.tp-link.com.au/faq-533.html

You may send an email to TP-Link tech support (support.uk@tp-link.com) to let them check about this issue.

What's the firmware version of your VR200v?

Could you show us a screenshot of the Enable the Virtual LAN Ports feature settings and the IP settings on the 9980? And what's the firmware version of your 9980?