Unable to format text in Vivaldi browser

[wpcoe]

For a while now (maybe a month?) I have not been able to apply formatting (bold, italic, underline, etc) when composing a post in Vivaldi browser.  I think it is some quirk with Vivaldi, and not something broken with the forum software, but a post for help on the Vivaldi forum went unanswered, so I thought I'd check here to see if maybe there *is* something that can be tweaked on the forum side.

 
When composing a post, if I select some text with Vivaldi, as soon as I click on any of the icons on the bar at the top of the compose form, the text un-selects.   And, clicking on an icon, like the B for Bold, before typing text doesn't result in the B being active and no formatting is applied to typed text.
 
Any chance this can be addressed from this side, since Vivaldi seems dis-interested in/unable to help?
 
I've typed this post in a Chromium browser, and all the formatting seems to work just fine.  Ditto when using IE, Edge and Opera 12.  Just Vivaldi, my otherwise preferred browser, has an issue with ThaiVisa.com.

[wpcoe]

Okay, it seems someone enjoys tinkering with the forum software?

 

I switched from using the Vivaldi browser to Comodo Dragon, a Chromium-based browser.  Both yesterday and today at about the same time (1015am) suddenly links opened in new tabs wouldn't load in Comodo Dragon.  e.g. I would view a forum topic list and <right-click> to open the thread in a new tab, and the tab would load the page, then suddenly it stopped loading pages, just black rectangles in the four corners of the screen.  I would copy the URL from Comodo Dragon and paste it into another browser and the page loads properly.  Come back to Comodo Dragon and it won't load.

 

Yesterday when this happened, it self-corrected within a few hours:  Later in the day I was again able to open threads in new tabs in Comodo Dragon with no issues.

 

What is going on?

[wpcoe]

To continue my monologue, the non-loading of forum pages in Dragon continues at random times.  The other day mid-afternoon it happened.  It just happened a half hour ago at 4:30am.  I discovered it only happens for short period of time, too, something less than 15 minutes in duration.  Annoying, but livable First World Problem.