what ip address on your computer or phone? check the gateway/router ip on them. Use that number to login. http://www.tp-link.com/us/faq-87.html

what ip address your computer can get when it is connected to MR3220 via cable?

for ipsec issue, we can try this, http://static.tp-link.com/res/down/soft/MR200_V1_Beta_160706.zip

hi, can you show us some screenshot? which firmware you have upgrade?

how many clients do you have? will it work better if there is only client?Wi-Fi signal disappear?

It seems that you tried to add this camera again with MR6400 router,and before logging into this camera,normally the camera should be plugged into your router by Ethernet cable,and your phone should...