Both my laptops have 5GHz buit always connect to Eero on 2.4GHz, with of course much lower speed. The adaptor is a Realtek 8821 802.11ac and so is enabled for 5GHz.

My computers connect OK to other 5GHz routers, the the problem likely is with the Eero.

So how can I make my Eero connect to 5GHz?