Scrollphat Hd issues

Hello, I’m new to the forum.
I just received my Raspberry Pi 3+ and a Scrollphat Hd.
When I run the test py scripts, or any py script, I get weird patterns on the led matrix.
for example, if I run the gamma-test.py, all Leds are lit up, then a lot of them shut down, then again. More or less the “pattern” is the same with any script. Even if I run the command to lit only a row of Leds. At first it lits up, then some on the leds turn down, then back lit up, an it cycles, also fading in and out the brightness. This Happens with all the scripts.
During the installation with the Pimoroni Dashboard I get those errors
Unable to install smbus for python 2!
Unable to install smbus for python 3!

I’m running Raspbian GNU/Linux 9 (stretch) on a Pi 3 B+

Many thanks, any help will be much appreciated

Just tested on a Pi zero and worked everything fine. Back on pi 3b+, issues are gone and everything working as expected.
Thanks again

Soldered on header or hammer header? Sounds like it had a poor connection initially. Hopefully it keeps working properly.