When designing the Elka-X we decided not to add MPE support due to a number of factors. The following Cherry Audio synths do support MPE mode: DCO-106 Dreamsynth Memorymode Mercury-4 Miniverse PS-20 W...
Try running the standalone version of Elka-X. Sometimes a firewall can block the host software's access to the internet, and running the standalone version can bypass that. Of course, also make sure t...