Voucher page refuses to stay open for some users

[cybrejon]

Customers complaining about the voucher page (with the input field to claim vouchers on) giving them inconsistent results. This is further confirmed by me after trying it out. On some devices, pressing the voucher button on the captive portal homepage will show the voucher page for a split second and then immediately sends you back to the homepage.

This is, however, inconsistent behavior. Voucher page sometimes remains open for long enough, and customers are able to claim their vouchers. Other times it functions normally.