It's possible that the laptop can't utilize the 5Ghz band, even though it showed as being available when you first connected. But, if you know that the laptop definitely can utilize the 5Ghz band make sure that your network adapter's driver is up to date.
For Windows 10, here are some things to try... https://support.microsoft.com/en-us/help/10741/windows-10-fix-network-connection-issues
The hidden network, though part of the HT2000W, cannot be connected to nor utilized.
With all of this said, if there isn't a particular reason for wanting your laptop to use the 5Ghz band the 2.4Ghz band does work well, and it actually has better range than the 5Ghz band. If there is a reason for wanting to use the 5Ghz band you can try the things listed in the link to see if any help.
Welcome to our community! The 2Ghz and 5Ghz bands have different ranges. If you move closer to your Wi-Fi Modem that may resolve the issue of not seeing the 5Ghz band. You can also try giving both the 2Ghz and 5Ghz SSID's a new unique ID using the HT2000W manual here using pages 4,5 & 6
On a side note, the Hidden Network SSID is used for our Wi-Fi Booster as it's connection point.