I saw the posts with simplex issues with openSPOT and knew a quick check with my other radio a CS580 on simplex was working only in one direction.
After about 2 hours maybe 3 of trying different combination of configurations on 441.000 MHz this is my conclusion.
The 868 has checkboxes for TDMA Simplex, Adaptive and Call Conformation. There is some information in the v1.18 programing guide. The most important box might be the Call Conformation box.
I can always transmit from the 580 and be heard on the 868. From the 868 to the 580 it does not work. What I see on the 868 is a brief transmission then a few seconds later the "No Repeater Found" popup. No indication on the 580 of any transmission from the 868.
Regardless if the Call conformation box is checked off or not it appears that the 868 is always expecting to receive an ACK from the 580.
The 580 does a Private Call ACK which I briefly tried, but was getting tired and frustrated with lack of progress and had already convinced myself the issue was the Call Conformation Box not checked was not being recognized by the 868.
Both radios on reduced power levels with the 868 on an antenna and the 580 on a dummy load. Audio on the 868 sounded good with a slight echo delay so I don't think I was overdriving the front end and had a reasonable hardware setup.
Looking forward to the next update.
Mike