I'm trying to reproduce this, and these are the steps I'm currently following, which are not reproducing the issue you describe:
1) Log out
2) Log in to ACP
3) Click Appearance > Styles
4) Click on Style Properties for a style that has no customized components (style 'bla')
5) Edit and save a style property (I was using one of the palette colours)
6) Click on Search templates in the sidebar
... style 'bla' is selected in the style drop-down of the search templates form
Would you be able to identify exactly what you did to see this behaviour?