Found the cause of the issue with unstable connection to the 5 GHz Wi-Fi access point

[KarenK]

I previously posted that I was having issues connecting to 5 GHz Wi-Fi. 

Since my thread has been closed and I cannot add new posts there, I am writing here.

It turned out that the issue was caused by 802.11d being enabled in the wireless adapter settings. I disabled this option and now my laptop switches between 2.4 GHz and 5 GHz instantly. Problems with connecting to 5 GHz have disappeared.

I think it would be good if Asus did not enable this option by default on laptops. I wasted a lot of time trying to find the cause of my issue.

[KarenK]

It would be nice if the moderators could add the solution found to my previous thread, which is currently closed. Moderators should probably also inform other users who had the same problem about the above solution. For example, @sidarya31  also had a similar issue.

[Falcon_ASUS]

@KarenK 
I have re-edited your updated content into the original article and set it as the best solution. 
Thank you for your information sharing and updated replies.