It's not a big job to unbolt the seat from the floor pan, and have a good look under.....much easier than peering under seat to see what is not working.
You will need to unclip any electrical sensors, and remember to re connect afterwards.
Some grease or oil spray on parts will be helpful......and while you have that in your hands, ease up the gear lever ring, and give the gear leaver and its moving parts a shot of lubricant, preferably grease.