Strange connection time out problem

Hi, I have a strange problem, here is my network

                                                                      Ip sec VPN (from Android)
                                                                                         |
                         192.168.100.0/24                                    | 192.168.10.0/24
Internet======Optic fiber router====>dmz====>Mikrotik router
                                                                                         |192.168.10.0/24
                                                                      LAN Pc's  -- | -- cubietruck (wg0) =====> remote lan 10.0.0.0/16
                                            
I have configured wireguard for site to site connection on cubietruck (Armbian next kernel 4.14.18).
I have added a static route to Mikrotik to pint to the ip of cubietruck for the subnet accessible from wg0 interface.
It was working fine for 2 week but after a power outage, there is a strange behavior.

When I connect to Mikrotik through Ip sec VPN (from Android) I can reach remote lan 10.0.0.0/16 and everything works fine.
When trying to do the same from lan pc's, even if I can ping the remote lan machines, the http connection starts but then it times out.

I would appreciate any input-pointers on how to debug this behavior.