Seems to be a new issue with 5.1.8 (as least had it not before).
In a longer chat nothing is transmitted any more. Both sites are signalling busy ( and do not send). For varaHF Softmodem frequency is free.
Had this issue yesterday, and also today. In both cases the partner was also using varAC 5.1.8 - with same situation (nothing sending, signalling of busy).
73 de Roland DK4RH