Reported Version: v0.2.0 (latest) | Mods: none | Can replicate without mods? Yes
OS: Linux | CPU: AMD Ryzen 7 3700X | GPU: AMD Radeon RX 6700XT | RAM: 32GB
I have encountered the lack of trajectory lines and erroneous landed status twice now (evidenced in one case by the ability to perform landed experiments from orbit).
In the first instance, a simple mun lander that was intended to rendezvous with another craft in orbit experienced some awkward lander-leg snapping/jumping while performing the EVA and got stuck with the landed state. After the navball numbers claimed that I had an orbit in excess of 40km PE, I checked on my rendezvous craft and returned to find that my lander had suddenly lost ALL velocity and was now beginning a plummet straight down. Teleporting the craft back into orbit with the cheat menu actually restored its in-flight status.
In the second instance, I had a lander to decouple from a recovery craft with two stages left; decoupling the lander would take the final stage off the stack while others remained un-fired. As soon as I did this, I lost control over the manned lander and BOTH craft became erroneously landed. I EVAd the lander kerbal and regained control upon re-boarding that vessel. Both vessels were still in orbit at this point. I burned to deorbit the lander and checked the map to find that the rendezvous craft was still too close by; I left the map and watched it plummet right by the lander: it had suddenly lost all of its velocity and started its own plummet. Teleporting the rendezvous craft back into orbit with the cheat menu restored in-flight status. I completed my mun mission and attempted to re-orbit the lander, but the erroneous landed status stuck with it all the way into orbit (confirmed only via navball numbers). Teleporting the lander via cheat menu DID NOT restore in-flight status (I tried twice with different orbits).
FWIW, the rendezvous had to be done nearly blind and the rest of the mission was plagued by faulty RCS thrusters, parachute deployment failure, and was ultimately saved by the unusually-safe-splashdowns bug (50m/s+ landing with 2/3 drogue chutes deployed and 0/3 normal chutes was stressful, to say the least, after all of that). After that session (and looking up the bug), I'll be keeping an eye out for seemingly high-risk moments; maybe I can pull a save or two off that'll reproduce it consistently on my end in the future.