I occasionally experience that Studio 2019 SR2 changes the text font, in my case from Frutiger to Minion Pro. This does not happen systematically. There are no tags in the editor view, except a /cf if you display "all content" instead of "all segments".

Here is a snippet from the source icml:

<ParagraphStyleRange AppliedParagraphStyle="ParagraphStyle/Product spread%3aCollection title_smaller">
<CharacterStyleRange AppliedCharacterStyle="CharacterStyle/$ID/[No character style]" FillColor="Color/Baby Grass Shade" FontStyle="77 Black Condensed" PointSize="18" AppliedLanguage="$ID/English: UK">
<Properties>
<Leading type="unit">18</Leading>
</Properties>
<Content>Table and chair sets</Content>
</CharacterStyleRange>
</ParagraphStyleRange>

Here is a snippet from the target icml:

<ParagraphStyleRange AppliedParagraphStyle="ParagraphStyle/Product spread%3aCollection title_smaller">
<CharacterStyleRange AppliedCharacterStyle="CharacterStyle/$ID/[No character style]" PointSize="18" FillColor="Color/Baby Grass Shade" AppliedLanguage="$ID/de_DE_2006" FontStyle="77 Black Condensed">
<Properties>
<AppliedFont type="string">Minion Pro</AppliedFont>
<Leading type="unit">18</Leading>
</Properties>
<Content>Massivholz-Kindertische und Stühle als Sets</Content>
</CharacterStyleRange>
</ParagraphStyleRange>