[44net] Mikrotik IPIP help/favour please

I've just powered on a Mikrotik hAP lite which I believe I had recently correctly configured, i.e. traffic between the internet and my 44net subnet was flowing on its ether2-4 ports, however appears to now be dropping incoming traffic to my subnet with Destination Unreachable ICMP frames. I have checked and re-checked my config steps from scratch with no success. Would someone with an IPIP-connected 44net allocation, a working Mikrotik setup, and 5 minutes of spare time mind please running "/export hide-sensitive" on their Mikrotik and sending me the output so I can diff it, to find my inevitably stupid error? Thanks.