Hi Jakob,
You’ve run across an interesting bug! We’re currently working on a fix for this to ensure Concatenate respects the input arguments and returns rich text when required. This would also enable fun things such as using our Rectangle formula to draw bars (something Shishir is quite fond of).
Your suggestion of using Join is a great for now though I don’t believe you need to wrap the arguments with a List formula. Based on our current behavior, the only requirement is that the arguments have a rich text value. Ex: your input should be bold, italics, etc. This image gives a basic example. Notice the first row gives the desired result while row two has issues. The only difference being pure text vs. rich text.
It’s also good practice to avoid Nth where possible. If you have a well known row that you want to refer to you can reference the row and pick values from it by using an @reference. The little snippet below shows the difference.
I appreciate your contribution to our Community as we get things going. Keep the insights and suggestions coming.
Nigel.