I’ve seen the same behavior as well, glad this thread beat me to it.
I’ve been experimenting with DIR-TO/Radial IN as well but have been coming across odd responses with it recently. Programming a radial inbound (roughly 30 degree intercept to final approach course) on an RNAV 4R approach into DTW, MCO 18R, and DEN 16L so far, the fixes on the approach sequentially delete themselves....you can watch it happen about 3 seconds apart.
In other words, with managed speed, altitude, and NAV selected, the IN-BND and intercept fixes display correctly on the ND very briefly then every waypoint will delete itself afterward one at a time. Eventually, the aircraft slowly turns direct the runway selected, but trying to reload an approach then causes a hard CTD (nothing in the error logs either), so if I get into that situation, I’m forced to disconnect AP and fly visually.
I know that’s vague, and very odd, as I’m trying to still recreate and investigate but does anyone else have see this issue?