Hopefully this will help.
When Nv2 wireless link experiences disconnections and in log section most of the messages are 'control frame timeout', then make sure that the router's RouterOS version is at least v5.14. v5.14 introduced several improvements for the Nv2 wireless protocol. Second suggestion is to lower the transmit output power of the wireless cards if the signal of the link is strong. We suggest to use tx-power-mode=card-rates for lowering the tx-power of the wireless card. If the problem continues try to use different wireless frequency that might have less interference.