Text formatted by user-created style does not carry over to Mobi file on compile

Product: Scrivener (Version: Beta (845700) 64-bit - 24 Feb 2020)
Platform: Windows (windows 10)
Name: John Crabb

Bug description:
A blockquote style which I created does not seem to carry over to the compiled Mobi file. It is still present and the text is correctly formatted in the manuscript but gets lost on compile. This is a new thing with the Version: Beta (845700) 64-bit - 24 Feb 2020, it always worked with previous versions.

Steps to reproduce:
Created a blockquote style by ‘creating style’ from a formatted paragraph. Works in m/s but the blockquote formatting was no longer apparent in Kindle reader when I opened the Mobi file.