At least on Mindanao, we still have some irregularities with the darbar shown on map.
Today, there was a bomber mission of 6-7 formations .reported out of A8 going south. I immediately took off to intercept them. As there was only a very small darbar on the map I (and others) assumed a NOE raid with a lone straggler somewhere in the sector.
Only when the mission was about to enter the dar circle, and I had crossed into the same sector as the buffs, the darbar suddenly jumped to full length. A few moments later I spotted the bombers and several escorts - at 8K! I wasn't the only one: Several players asked "how did they climb that fast?" - Having seen no darbar either, they wondered how the bombers could suddenly pop up to altitude.
Yesterday Rolex, Mosq and me did a few tests with inconsitent results. When I took off from a base and climbing above 500ft I was not showing any darbar for Rolex. We switched roles, and when he did climb over 500, I saw his darbar.
We continued to test dot & dar at a different location on the map, with Rolex being on the enemy side. Dot dar always worked as expected, but again darbar was giving erratic results. Sitting in the tower of a CV, I didn't saw the darbar an enemy fighter should have caused in the adjacent sector. Mosq, being in the same sector had that darbar, and it also showed as a green darbar for Rolex. On the other hand I saw the darbar caused by a single enemy con two sectors away.
Then a friendly contact passed through my sector, but never showed any darbar for me, but the other two guys saw it. All tests had been conducted in a quiet corner in a very lightly populated offpeak arena. I'm not sure if in this case it can be of any help, but I had recorded the whole test session and could send it in if required.