C206 pilot reported engine temperature increase and rough running engine in cruise. Pilot diverted and landed.

Narrative

I depart from ZZZ to ZZZ1 around XA:00 am this morning. During cruise to ZZZ1 on a IFR flight plan communicating with 118.1. I saw the #5 EGT temperature drop to 0 suddenly and the CHT start lower too and the engine starting to make coughing sounds. I enriched the mixture with no changes to the problem; and then I ran through the POH. Compared the EGT and CHT and oil pressure. After I quickly decide to go back to home base since I'm close to it and have a Mechanic check it instead continuing my trip. I told the Approach I have an engine roughness issue and I'd like to divert to my home base airport ZZZ2. And they ask me if I need to [request priority handling]. I said negative and I'm good so far just need to change the destination. Then I was switched to Regional Approach on 135.97. They descent me to 4;000 feet MSL and [requested priority handling] for me while descending through 4;000 feet MSL. #5 EGT Temperature came back and engine seems back to normal. When leveling out at 4;000 feet MSL the # 5 EGT continue to the bottom and #1 EGT Temperature went high. I continued flight and landed safely at ZZZ2 airport. I hand over the plane to the Mechanic after landing.