I used to run Continental GP5000 TL & Stans Sealant. Without a significant flat causing leakage, I'd get 3 months until 50% of my 40ml fill was gone.
Any flat will consume sealant shortening the time frame between sealant top off.

When Continental went to GP5000 S TR they lightened the tire by removing one of the sealing layers in inside the tire.
I could not longer get the tire to seal at all with Stan's Sealant. Tires would go soft overnight.
I switched to Orange Seal Standard and tires would retain air much better. However I'd get to 50% sealant level in only 6 weeks.

I'm now servicing my sealant level monthly on two bikes. It takes less than 15mins total to top off them both.
I would rather spend the 15min/month servicing tubeless in the comfort of my home than fix random flats beside the road.

Your tires, sealant and weather will result in a different time frame for servicing.

Hope this helps

Barry