It was brought to our attention by a number of customers of a failure to connect to 5GHz that happens after upgrading Windows OS. What will happen is devices are unable to connect to the 5GHz of the main router, while the 2.4GHz works fine.
If you are experiencing this issue, please get in contact with our technical support staff. They will be able to provide instructions to help update the driver of the network adapter to solve this.
Here is the link to our home support: https://www.tp-link.com/support/contact-technical-support/#E-mail-Support