Stovetop burners making yellow flames

My 1994 Holiday Rambler Vacationer is equipped with an Atwood 3-burner stove. It worked fine for about 10 months and now for the last month or so I’m getting yellow in my burner flames and soot on the bottom of my pots and pans. It’s affecting all three burners and I have done nothing to the burner controls other than normal off/on and adjust with the knobs on the stove front. My propane tank is half full and I haven’t added propane in about a year (I only use the stove for cooking and have no other propane use). Since all the burners are affected I’m thinking I’m having a regulator issue, but thought I’d run it by here before I purchased a new regulator just on a hunch.