It seems like the mouth of the toilet tank is close or almost at the bottom so it's inconclusive whether or not its the flapper or the gasket when I let the water drain to the bottom. However, I played with the flapper and the time between refills is not as frequent now.
The flapper in question is this Moen one -
https://www.homedepot.ca/product/moe...per/1001163148
I think I'll grab this Fluidmaster one and see if it makes a difference -
https://www.homedepot.ca/product/flu...ban/1000110879
Don't think it's an issue with the chain because the flapper opens and closes fine.
Just hope I don't actually have to swap out the whole valve flush. I tried removing the nuts that held the tank to the seat earlier and it just wasn't happening, lol.