My wife and I are mostly tandem riders, but she has an old Lemond Zurich road bike that she uses on an old trainer. It has 9 Speed Ultegra brifters on it. Recently, the right side brifter has a weird issue. The smaller lever (to shift to a smaller cog) just moves across without actually releasing the cable to allow the der to move down a cog. But, if I hold the larger lever from moving at all when I press the small lever, it shifts fine. When you just press the small lever, as you normally would, if moves the larger one a millimeter or so at the start of the small lever travel and that seems to cause the shift to not work. Any clue if this is repairable? She doesn't use the bike much so I don't really want to upgrade it. I am very mechanically inclined, but I've heard that Shimano brifters aren't easily repairable.
I am not sure of the model number as I can't find it, but a pic is attached.
Thanks