I've got some code that checks to see if there are some specific URL parameters, and if so, set a couple of cookies that can be used across subdomains. Looks a bit like this in the middleware:

const utmsToCheck = ["example_id", "example_key"]
  utmsToCheck.forEach((utm) => {
    const utmValue = urlPath.searchParams.get(utm)
    if (utmValue) {
      res.cookies.set(utm, utmValue, {
        httpOnly: true,
        secure: true,
        path: "/",
        domain: isProduction() ? ".mydomain.com" : "", 
        maxAge: 60 * 60 * 24 * 90, 
      })
    }
  })

On localhost, works fine. In incognito, works great. But on production with uBlock origin installed, these are not set. I've also tested and confirmed this with no array, just pure cookie set, it still is prevented in the window with an adblocker.

I'm absolutely perplexed at this problem, since it's clear the cookies are being set correctly in non-adblocked contexts. Am I missing something?