Bug when updating InDesign from Excel table

[KC031]

I suddenly have a strange problem when I update a document with many tables in from an Excel file (.xls). I update my Excel file as I have been doing for the past 2 years, but when updating InDesign, the last cell suddenly gets a different font in every table. 

I can solve it manually by clicking "delete all overrides", but I don't want to do this every time for 100+ tables (when I change this, InDesign doesn't memorise the change and the same problem happens the next time I update the contents)... 

The strangest thing is that I have 8 similar InDesign documents (same styles, source from same Excel file), but this only happens in one of them.

If anyone would be able to help me, I would be very grateful!

[Willi Adelberger]

When nothing is selected that Cell and Character Style is set to [None].

[KC031]

Thank you for your prompt reply!
I actually have a style implemented on all the body cells of my tables. However, when I update the Excel, the style is overwritten somehow

[Willi Adelberger]

It is happening if bevore the text tool was selected a Cell or Character Stayle is active or if in the selection it is the style applied.