Titillium Web font-weight issue

I have a problem with adressing the font of the widgets in my footer.

www.dqsurgical.de

I used the standard wordpress text/html widget within the footer. The html code of the first column is:

<p style="font-family: 'Titillium Web', 'Helvetica Neue', Helvetica, Arial; font-weight: 600; font-size: 18px;text-transform: uppercase;">Leistungen
<p style="font-family: 'Titillium Web', 'Helvetica Neue', Helvetica, Arial; font-weight: 400; font-size: 18px;line-height: 150%;">individuelle Beratung</br>Herstellung</br>Inverkehrbringung</br>pünktliche Lieferung</br>lebenslange Garantie

The remaining columns are similar. If you go to the home page, it works fine, but if you visit another sub-page, for instance www.dqsurgical.de/impressum, you notice that the complete column is bold, not only the first line. I tried to fix this with the developer tools of my browser and it seems to be an issue with the font. I had issues with Titillium Web before, for example it was displayed very unsharp when selected as the default font in the customizer. I fixed this by selecting a different font, Helvetica Neue, and manually using Titillium with css or html. This seems to be another issue related to Titillium.

I would appreciate any kind of help.