Outlook is constantly refreshing - what can I do?

Same here, happened for the first time today, clearing cache + cookies helped for now. This is my work e-mail so I really hope Microsoft is going to do something about it.

I am using Edge on a Macbook (Sequoia 15.3.1).

In case you don't want to clear caches or history, you may try this developer way.

1️⃣ Press Ctrl + Shift + J (or Ctrl + Tab + C in some browsers) to open the Console in Developer Tools.

2️⃣ Click on the Console tab. You will see tons of errors and logs—never mind those!

3️⃣ Copy and paste the following code into the console and press Enter: 

1️⃣ Prevent Page Reload
window.location.reload = [removed_js] {
    console.log("Reload blocked!");
};
window.location.assign = [removed_js] {
    console.log("Navigation blocked!");
};
window.location.replace = [removed_js] {
    console.log("Navigation blocked!");
};

// 2️⃣ Prevent Refresh via Keyboard Shortcuts
document.addEventListener("keydown", [removed_js] {
    if (event.key === "F5" || (event.ctrlKey && event.key === "r")) {
        event.preventDefault();
        console.log("Manual refresh blocked!");
    }
});

// 3️⃣ Prevent Leaving the Page (Back/Forward Navigation)
window.onbeforeunload = [removed_js] {
    event.preventDefault();
    return "Are you sure you want to leave?";
};

// 4️⃣ Disable Console Logs to Prevent Tampering
console.log = [removed_js] {};
console.warn = [removed_js] {};
console.error = [removed_js] {};
console.debug = [removed_js] {};

Done! Now, the browser won't refresh, navigate away, or let you reload via shortcuts.

If you want to undo this, simply refresh the page manually or restart your browser.

I am experiencing the same thing. When deleting browsing data, I am automatically signed out out everything. I will try solely logging out of outlook.

I have a similar issue. Noticed that it occurs only when i try to open or write emails that contain attached files (images, pdf, etc.).

Tried logging out and signing back in, helped for a short time.

I tried this, but it only lasted a couple of days before the same issue returned.