"Difference in behavior when injecting JavaScript code into frames using 'allFrames: true' vs 'frameIds: []' in amazon.DE vs amazon.COM

Question

My extension is supposed to inject js-code to scrape the active tab for images when the popup is opened.

I encountered a problem in amazon.DE where the JS-code breaks at the point of script injection, but not amazon.COM! No codes after the injection get's executed and I get no error message in the consoles of both my popup nor the active Tab.

I think the issue comes down to the code being injected into all [frames][edit], not all of which share their host with the active tab.

From my manifest.json:

{
    "manifest_version": 3,

    "permissions": [
      "storage",
      "unlimitedStorage",
      "activeTab",
      "scripting",
      "webNavigation"
    ]
}

The code I use for injection:

async scrape() {
    let tabs = await chrome.tabs.query({ currentWindow: true, active: true });
    let tab = tabs[0];

    let frames = await chrome.scripting.executeScript({
      target:{tabId: tab.id, allFrames: true},
      func:grabImages
    });

My bug testing has yielded the following:

• the script always gets injected in the frames I care about (main frames). It can do what I want it to do there.
• if the script injects via allFrames: true into amazon.COM I don't have an issue
• if the script injects via frameIds: [list, of, ids, of, all, frames] it breaks with the error message: Uncaught (in promise) Error: Cannot access contents of the page. Extension manifest must request permission to access the respective host.
• if the script injects via allFrames:true into amazon.DE it breaks without any error message
• the code works fine on the amazon.DE homepage, it only fails on the product pages
• if I click my extension fast enough, before the product page of amazon is fully loaded it works (kinda, it is missing some images that are present on the fully loaded page)
• the amazon.COM product page has 3 frames, the amazon.DE frames has 7.

My questions are:

1. What is the difference between injecting via allFrames: true vs injecting via frameIds: [] that leads to the difference in outcome?
2. Why does "allFrames: true" work on amazon.COM but fails silently on amazon.DE?