Why is my Jeep Sahara getting stuck in gears lately?

What is your question?

I have a 1994 Jeep Wrangler Sahara w/ manual transmission. The fluid levels are fine. A few days ago when sitting at a light, it would not shift into 1st when the light turned green until it was pushed forward about 1 foot. I thought that was it then it did it again a few more times the following day - again, coasting got it into gear. Same thing then yesterday. I am trying to get an idea about what this could be. Research seems to show me everything from my gearbox to my transmission to it could just be a transmission hose and I should add something called lucas oil. Thanks in advance for any answers and/or advice.