I have the same issue as other users. All my tabs in Firefox are loading on start-up. I use the extension because Google does not load when I am connected with the desktop app only. Somehow with this plugin I bypass this issue.

I have tried all the commands around the tabs loading in Firefox config but it does not matter, the extension bypasses them no matter what. Only deactivating the extension resolves the issue.

I tried deleting and re-adding the extension. Nothing at all. It is sad. We pay for this service and it doesn't work. Please fix it. The issue happened to me yesterday as Firefox updated to latest version.

Nord was pretty good and fast, but...
Since last year their browser extension has been secretly throttled. This was confirmed with their devs after multiple emails to support. They never told us about this throttle and the website continues to advertise that they do not set any limits. Most likely their support even dont know about it and will tell you otherwise, which will just show how they can make such serious changes even without careful considerations within their team.
I gave some time to see if they will fix it but after a few months it didnt sound like they cared at all. If you are reading this you probably are interested in using the extension and not the desktop app, so my advice is dont get Nord now unless you are good with being slowed.

Update:
It is the case. Anyone can try to download a file and see for themselves it can never go above a certain speed. I see some previous reviews that mention this too. Just like I said pretty much no one other than devs knows about this.
Ticket 15039623

As of June 2024, this extension severely throttles internet connection speeds.

Using NordVPN without the extension is no problem at all, but the browser extension quite literally slows your experience to a halt. It's unusable. If you haven't purchased a Nord subscription yet, and you are hoping to make use of the browser extension, look elsewhere. All of the 5-star reviews for this extensions are likely out of date, and or posted by people provided with financial incentive to do so.



TL;DR
Steer clear.