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.