Experienced similar situation when we have either SSTP or IPSec configured with RUT240, using Mikrotik CCR1036-12G-4S-EM as the VPN Server. We are observing very degraded performance when Tunnel is configured. Without Tunnel, we are seeing throughput in the range of 15 to 21Mbps, but when either SSTP or IPSec tunnel is configured, throughput is drastically reducing to 2-3Mbps with the client connected to same CellID (LTE Network) and with signal remaining in same range. Not sure, what issue, but looking at earlier discussions on this topic, what is concluded? Is it the latest firmware on RUT240 is the cause? If yes, is there any fix available?