You try to log into my.wbs from your iOS device (using Safari) but it simply redraws the log in page and does not log you in.
- On your iOS device select settings (click the images to magnify)
- Select Safari
- Select the 'Block Cookies' option.
- Ensure it is set to allow cookies (the default and recommend option is to 'Allow cookies from websites i visit). If it is set to block cookies then this may explain login problems.
As to why this cookie setting has changed... no idea... but there is a discussion thread about this on the Apple site suggesting it is a wider problem.