Absolute KDE newby; not sure where to ask my question. Please advice me if I should ask my question elsewhere. Also: English is not my first language.

Am running KDE Neon/Plasma:

Operating System: KDE neon 5.17
KDE Plasma Version: 5.17.4
KDE Frameworks Version: 5.65.0
Qt Version: 5.13.2
Kernel Version: 5.0.0-37-generic
OS Type: 64-bit
Processors: 8 × Intel® Core™ i5-8250U CPU @ 1.60GHz
Memory: 3,7 GiB

Linux willem-Aspire-A315-53 5.0.0-37-generic #40~18.04.1-Ubuntu SMP Thu Nov 14 12:06:39 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux

Installed Handbrake with Discover.

When I run handbrake essential parts of the user interface are missing, please have look here: https://i.imgur.com/kU14Z2A.png.

Anyone here know how I can get the full interface to become visible?

If there is more information I can provide, please let me know. Thank you.

Not sure Neon is the right Plasma version for you, I use Kubuntu which is a full OS (which Neon is not) and have no problems displaying everything correctly. According to the Handbrake documentation, you need at least Ubuntu 19.04 or later, previous versions are not supported. Since Neon is based on Ubuntu 18.04, this might be the problem.
Also please keep in mind that Neon is a showcase for Plasma, everything non-KDE is not supported and might well break or not work correctly. See also https://neon.kde.org/faq

Thanks!
will have a look at Kubuntu.
very much like the look, speed, and slick experience of neon, though. I hope Kubuntu is comparable.
Good job!

Thank you for your quick response.