Routeros-mipsbe 6.13 Routerboard 450G FW 6.10
IPv6 firewall rule: forward from [4-part prefix]::/64, no other data, action=accept;
addresses come from network behind the firewall.
This works now for PING only.
In the past (when set) it also worked for (tested) RDP, HTTP and HTTPS.
One day it stopped working, without any manual change.
Only possibility to make it working again is to set a rule accepting all TCP, or accepting completely all.
SOS - what is wrong?