The Hedge Ascent landmark is still broken 1.4.3 Steam, although there is progress. The recent patch unlocked the item-credit on the data tab in the Sca.b menu, however it doesn't mark the location on the map, nor does it give credit for the location for the new "Been There Done That", thus this bug continues to block the new achievements, even though I was able to unlock the 100% achievement, super annoying as someone who waited over a year to have see the bug resolved.
One important point, the patch notes seem to indicate a belief that this is related to old saves prior to 1.3, however even a fresh save in 1.4.3 for me exhibits an issue with unlocking the Hedge Ascent landmark. This has been true in prior 1.4.x versions as well with newly created save games. My install of grounded has been verified and I've re-installed from scratch within the last few months. I did have had very old early-access versions of Grounded installed on this PC via steam (a format of the PC is long overdue at this point). The same is true of another PC in my household, which also seems to exhibit the same behavior when starting new games.
Just based on the way this was resolved, I'm assuming the devs have had trouble reproducing the issue, and unfortunately the band-aid wasn't very effective. I've taken the initiative to pack up a brief history of my different save files (head versions only), and my appdata\local\Maine folder (It sure seems like perhaps this is a bug that lives in the shared config of an install, so I was sure to get this), with the hope that someone can reproduce this issue and resolve it fully.
You can download my save data here, be mindful of the included readme which details the date each world is from, and some quick notes related to this issue where they are known:
https://www.dropbox.com/scl/fi/mzj0ycpgqlo7ejoyov2nz/Grounded-Hedge-Ascent-Bug-Multiple-Saves-plus-Appdata.zip?rlkey=g0x30kshq7gmzl6got3xo2014&dl=1