404 error on first load on Chrome but not MS Edge

Hi there,
I have a Shiny direct app served by Shinyproxy. It has been working fine for ages, but recently on Chrome I get a 404 error when first logging in (using auth0 as the authentication provider). Weirdly, when I refresh the page, the app then appears fine and everything is normal. Additionally, when I use MS Edge to load the app, everything works normally and no 404 error appears.

Anyone know why this might be happening?

All the best,

Recently, I have been having issues with cookies. They tend to be intermittent. I am using SAML SSO. It would work in a different browser or in inprivate/incognito mode in the same browser. I can also go into the developer mode and navigate to the application and delete the cookies for that application then it seems to spontaneously start working.

Some ideas for trouble shooting, but I think these should be unnecessary.

Hmmmm… I do often use cookie ignoring and adblock extensions on my browsers. I’ll try to turn these off, clear cookies and try with an unaltered Chrome instance. Also, I have had problems with Opera, where it says the site is insecure, despite it using https and a ‘Let’s encrypt’ certificate. Still fine on Edge.

Thanks for the suggestion.

I was able to resolve this after a fashion. I implemented a cookie filter upstream, everything started to work. I am not sure where all the errors were occurring. I tried increasing the http header size via the spring boot mechanism and the application.yml. I also tried the recompiling trick for shiny. Neither of which seemed to do anything. One issue seems that there maybe are multiple endpoints with different http header requirements. EG DT::datatables has its own http endpoint for ajax throwing 403 errors. However, I was definitely getting 400 errors from other parts of the http stack.