This issue with the Barclay website has been reported by two others, so it looks that this is a problem with the website in Firefox where only the height of the image is adjusted and not the width.

• /questions/1390045 barclays (uk online bank) login screen is distorted (stretched too wide)
• /questions/1390241 Distorted graphics on online banking app

Unfortunately is accessing that PINSentry page only possible if you are logged in, so we can't check the CSS code. If you are familiar with using the Inspector then you can check possible CSS rules for height and width.

You can right-click and select "Inspect" to open the built-in Inspector with this element selected.

• https://developer.mozilla.org/en-US/docs/Tools/Page_Inspector/How_to/Examine_and_edit_HTML

@cor-el Thank you for your response and suggestions. As this problem appears to be unique to the use of Firefox as a browser I think it is up to Mozilla to examine the Firefox code along with Barclays who appear to have created a situation that restricts the choice of browser. I agree with @bluebottle47 ~1390241, that Barclays and Mozilla should "talk". Again many thanks for the advice so far. Alas another few hours wasted in self examination. MJRC

For me the fault appears to have been 'fixed' - Thanks to Mozilla? and Barclays?