I assume you have read some posts on pilot lights using the search function. If not, give them a look.
I would clean the pilot tube, just in case there is an obstruction that swells up with the heat to block the flow of gas. Many posts on how, tooth brush, small wire to scrape inside, even disassembly to clean. Pluss blow out with canned air or air compressor.
If this fails my guess is that your thermocouple is failing. Normally more like a light bulb, works or dead but this could be the odd one out. Another idea is to bend it a little closer to the flame to get more heat.
Never heard of pilot size changing, so keep us informed of the final fix!
2017 SLX 195RB
2021 Jeep Grand Cherokee Summit L 5.7L V8
Andersen WDH hitch, Renogy 100 AH Lithium &
200 Watts solar panels from Renogy
Prev. '14 Jeep Grand Cherokee Overland, gas 3.6 V6