We're having some unusual problems with input to an ASPX web page under IIS 10.
Input parameter contains %A3 for the UK Pound Sign symbol.
When the parameter string is accessed within the C# page source, the url un-encoding has been applied and we get a question mark instead.
Believed that this was due to the default codepage being incorrect, so added a Globalization setting to thw web.config file, specifying ISO-8859-1 and that resolved the problem. It had previously specified UTF-8, which I think does not support the pound sign as ascii 163 (hex A3).
This had been running in the expected fashion for over a week. Now, the problem has re-appeared!
No settings have been [knowingly] changed, no auto-updates applied, no international settings modified (as far as I am aware). So why is it now ignoring the codepage settings in web.config for that application?
Any recommendations?