Dominik Lackovi?

This is the screenshot – https://imgur.com/lnEIIPc

Steps to reproduce:

1. Open incognito
2. type url https://ak-varazdin.hr
3. see screenshot
4. after refresh it works

I can’t see how this is special configuration error. I am running full page redis cache. I already tried clearing cache multiple times. Both server cache and Cloudflare cache.

For example when I open link from Facebook in incognito – https://l.facebook.com/l.php?u=https%3A%2F%2Fak-varazdin.hr%2Fostanimo-aktivni%2Frezultati%2F%3Ffbclid%3DIwAR1Jn4zuAD6vkuao923q_ELgW3231ULGQxmT6n_bAIKjR60aqIxCvJVtumQ&h=AT2LuNYQ1KDGpzyuQqqZkOAm5iO7PthGjs8EXpMhCqF-ulTl6joGYUx94R1Nnsd3pwdEfoXSlSqMyaLBjHKl68g25K8tvZfHE3WVPdy2VY2X0CNbhbuCoq7Q4DTjQ9aEMg&__tn__=H-R&c%5B0%5D=AT0v46xhU-Xnb_uDmQc-EzVulldkqbeCF4nhrVCbmuDFjoNxNYo19gUXW-A0CnhpgBuwyeNCznJE8jBz4X_nrlIU9ymteD5HUAyFdj8EyeVATJWUE7rQKyHrnVh3LohddUgLy-R0i-1qsHVeySVIMl2pSgncru9SOYKFN6WclD8rOTT2BtcsY-YLuIKsNX0-H7pvOgEkHgSxu18RMNeOt2uGHg

it works. But if I try to open page from Google or directly typing url it throws exception.

Same issue on my 2 websites… :/

When i disable that option:Require AppSecret Proof for Server API calls it normally publish post to my Facebook page. Why was that blocking this?
Thank you!