Modern Vespa

I have had this bike for over six months and I thought I would bring up another issue. It is a 2019 GTS and most of you are familiar. It recently had a complete 30K miles service and runs great. When the bike is cold, it starts right up like a new one, but when it's hot, it struggles to start. The starter just doesn't have the power to do the job. It really struggles to turn over the engine. This problem has existed since I bought the bike, but seems to be getting worse. If I let the bike sit for over 15 minutes, it will start easier, but if I only let it set for 5 minutes or less, there are problems.
The battery is less than a year old and I recently had it checked.(no issues) The terminals/cables are like new and corrosion free.
Any ideas on what the problem might be?

Maybe this has been mentioned before, but have the valve clearances been checked?

https://static.nhtsa.gov/odi/tsbs/2020/MC-10178216-0001.pdf

Interesting, makes sense, but is there no fix for it?

I guess replacing the camshaft + decompressor with a correctly matched set would fix it

Also using a lithium battery has more cranking power so could mitigate

A bottle of cold water to pour over the head, might be cheaper

Does anyone make a higher torque starter for the 300 GTS?

Just get an LiFePO4 lithium battery - no more high compression starting woes.

On this warm/hot situation, and the oposite if battery is cold, under 5c.

The Lithium battery seems to have solved the problem. I installed a 12 ah Banshee battery. I rode around in the 95+ degree heat and made sure that the engine was hot. I shut down the engine, waited around for a minute or two and restarted the engine about a half dozen times. Not a single time did the started balk. It started up every time like it should.
Thanks for the help.