@Offdave 

Hi,

Was this firmware update offered to you by the router itself or did you download it via a download link that you found somewhere?

You can only get rid of the watermark by either downgrading to the a previous non-test/beta firmware (if the router allows it) or wait for the next non-test/beta firmware to be released and then upgrade to it.

Apparently there is a newer firmware version for the "EU" model that just hasn't made it onto the various regional webpages of TP-Link yet. You could use the translation feature of the Chrome browser to translate it into your own language.

https://www.tp-link.com/de/support/download/archer-mr500/#Firmware

  @woozle 

Hi @ woozle,

Thank you for your helpful replies.

I saw the 230103 firmware here:

https://community.tp-link.com/en/home/forum/topic/586804

I didn't have the Tiscali/Fastweb problem this firmware was intended to solve, but I was suffering from frequent disconnections and was trawling through the posts here looking desperately for a cure of some kind and, well, I landed on the page above which had a more up-to-date version of the MR500 firmware. I thought it was worth a try. The update went without a hitch -- apart from the "Confidential Only For Test" watermark on the dashboard screens. I see now that the link to the file has the word "beta" in it, but the word doesn't figure in the post or the title of the firmware version itself.

I tried rolling the firmware back to the original version (220517) but the router refused the upload.

I'd seen the 230414 firmware you mention in your second post a little earlier. I believe it was developed to patch a security hole that has been discovered by a German consumer group. The posting software here won't let me include a direct link to the story, but it was on the guru3d website and references a "wps pixie dust vulnerability".

I didn't install this patch at the time because I was focused on wrestling with my dropped connection problem, but I have now, and -- just as you suggested -- the pesky "Confidential Only For Test" watermark has vanished. The patch also changed (updated?) the ISP file to 23031701 for some reason. Which was surprising, but -- assuming it doesn't cause any connection problems -- is fine by me. The most recent ISP file I'd previously been able to find (23021501) was intended for every 4g router except the MR500...

Thanks again for your help.

-- Offdave