can't reach to my internal network

Hi every one
I have two networks first 192.168.1.0/24 which is my main network that my server is in it with 192.168.1.3 IP address and the other network 192.168.0.0/24 which my clients are there the comunication interface is MPLS there are two mikrotik router board in each network first Ethernet port is connected to the the MPLS modem second Ethernet port is connected to internal switch in both places I have Internet modem which IP address are 192.168.1.1 and 192.168.0.1 on the modem I set a rule to send the 192.168.1.0/24 and 192.168.0.0/24 traffic to the mikrotik all the gateway on my computers are the IP of the modem, it was working fine till I update my mikrotik firmware to 6.43.2 after updating I face this problem: I can ping the computers in 192.168.0.0/24 from my server but they cant ping me unless I put my server Gateway address to my mikrotik IP address as soon as I change the gateway to 192.168.1.1 which is my modem IP they cant reach me I did trace my server IP it reaches my mikrotik insde the network but I dont know why it cant find my internal IP addresses.
any one can help on this?
Thanks