It has been 5 years since it was first suggested the access control feature shouldn't be applied to guest networks: https://community.tp-link.com/en/home/forum/topic/177236

This other thread from last year links to a couple of other times it has been reiterated

https://community.tp-link.com/en/smart-home/forum/topic/621240

This is a very basic feature that users need.

We should be able to have access control enabled for the main network, yet disabled for the guest network.