@EeveeTinn
You are not alone. It hasn't always been that way but it certainly appears to be happening recently. I think it started with one of the patches but I'm not exactly sure when it did start happening in my game.
I mostly go to Mt K on daytrips. I haven't done a multi-day vacation or played a household living there. I used to be able to queue the same option after a sim got back to the sign but that is no longer the case. What I am seeing is that all the hiking options do what you describe after you do an option the first time. For me it's not just the Meditative Walk, it's all of them. You can't repeat any of them on a single trip to Mt. K. The action shows in the queue initially but as soon as the sim reaches the sign, the action disappears.
But if you travel out to another world and come back later, you can do them again but only once each time you travel in. I'm not sure if that will work between zones in Mt. K as I haven't tried it, but it should.
Hope this helps.