Mails diisplayed in the Gmail Inbox list show the attachment icon and spend long times 'Loading' when actually three or five lines of text is all there is and no attachment is ever actually loaded.

Stop / start FF does not ALWAYS clear this behaviour. The same email repoened shows the attachment icon, the 'Loading' message and no visible attachment.

Stop / start the PC has no effect.

The old days of XP there was a way to show each email as HTML where faults might become apparent. Is this feature available in Win10 / Gmail ?