Lost CSS styling on all sub pages – permalinks issue?

Hi all,

I seem to have a lost my CSS on all sub/child pages. I suspect (from searching the problem) it has something to do with changing my permalink structures to the post name structure. Seems strange, because all my top level pages are styled correctly. Images seem to be unaffected.

Here is my top-level home page: https://thamesvalleytennis.com/
Here is a sub/child page: https://thamesvalleytennis.com/our-services/cardio-tennis/ (located under the ‘Services’ drop down)

Thanks in advance for the help!

Kind regards,
Steve
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