Odd typing behavior on forum postings w/quote - no spacebar.
Using current Vivaldi on KubuntuForums.net. OS is KDENeon 5.8.4 (for those unfamiliar it's Ubuntu core with Plasma 5 DE, aka KDE, but customized and more up-to-date than generic Kubuntu). Forum software is vBulletin® Version 4.2.3.
When posting normal comments using "Reply" function there are no issues. If I use "Reply with quote", the spacebar ceases to function for that post. No spaces in typed text regardless of attempts to include them. I have discovered if I back-arrow I can add spaces back into the text, but not at the end of the line during normal entry.
To be clear, the above behavior only occurs using "Reply with quote" function. I'm not 100% sure this is Vivaldi's fault, but with Chromium this does not happen. I haven't tried any other browsers. I will poll the forum to see if any other Vivaldi users have the same experience.
I'm going to go out on a limb and says the fault does not lie with Vivaldi.
Another user has now reported the same behavior using Chromium but Vivaldi works fine for him. For me, it's the reverse.
BTW, the forum in question doesn't belong to me.