The whole concept of “Octopus uses renewables so is not impacted by gas prices” needs to be challenged. The supply arm of Octopus by power from the grid. They can only buy the power from renewable generator but the electrons they supply to you come off the grid and are mixed with all the other ones
All generators sell their power at wholesale prices. Which in the UK market are not different for different generators! They are the price for the most expensive generator in use to meet overall Uk demand.
So whilst Octopus are buying wind, solar, hydro power your individual power may actually be coal generated and costs Octopus the same as gas generated
It’s complicated where a group also has generation. As Octopus may be/are generating with wind. But these are separate companies: Octopus generation is making money by generating at wind prices but selling at gas prices whilst Octopus supply is losing money as the price cap means they are selling at lower than wholesale prices