Why are all payment options not always visible at checkout?

[KokieChick]

I am seeing a few different checkout options when I run test checkouts on my Dawn theme 2.0. And I am not sure if this is a setting for Shopify or per theme.

I see Express Checkout shows sometimes which only gives "Shop Pay" as an option. And other times it shows just 3 payment options - "G Pay, Shop Pay and PayPal" and then other times it shows all that plus credit card. I want people to have all the options I have offered at all times. How do I set this?

[jax5snow]

I am having the same issue with PayPal not showing at check out & I'm also using the Dawn theme but version 4.0.0