How do I turn off the Telephone number formatting in the browser window.
Skype Telephone number Formatting in browser
skype for web
You have to deactivate or uninstall the Skype Add-on.In newer versions there is also the option to just turn the highlighting off in the settings of the Add-on.  Here is a link to the Skype FAQ:https://support.skype.com/en/faq/FA657/How-do-I-use-Skype-Click-to-Call