BBEdit 13.5.2 : "Compare" features not highlighting difference

[Leng K]

I upgraded to version 13.5.2 lately and since then, I've not been able to get the compare feature to shows the differences in copy content on 2 HTML files or text file. It'll only highlight only 1 word at top. 

I often have 2 new files open (without saving them) and pasted the 2 copy into the working file and select 'Compare' via selecting the 2 files to compare.  

No setting has been changed during the upgrade. Does anyone know what's causing this?

Thanks.