There is a gear select adjustment that may or may not be an answer, fuggled first gear engagement dogs while not common, do happen. (inside the cases on transmission gears)
the adjuster is seen at the bottom of this pic.
here's the procedure from the manual.
The mechanics of the mechanism have the throw to first gear needing the longest movement of the shift lever so any problems tend to show up there first. many things can add up to poor first gear engagement, sloppy worn teeth on the shift lever/shift shaft connection is a favorite.
the adjuster is seen at the bottom of this pic.
here's the procedure from the manual.
The mechanics of the mechanism have the throw to first gear needing the longest movement of the shift lever so any problems tend to show up there first. many things can add up to poor first gear engagement, sloppy worn teeth on the shift lever/shift shaft connection is a favorite.