Sorry for the vague description as i do not know how to properly describe this problem.
When some web pages are loaded, the formatting will be the wrong size and in strange places. in addition every drop down menu appears without prompting and it seems to not be able to load certain data.
This only seems to occur on web pages that require a login, and only after they have been logged into or I am on the login page. (parent pay, squadlist,
It occurs on chrome, internet explorer and Microsoft edge on two windows 10 PCs.
It also appears to occur on an apple tablet using its browser safari.(parent pay shown here) 
What is happening and how worried should i be?