Random High World Latency

I play WoW on a laptop and a few months ago I bought a monitor and now I play WoW while connected with an HTMI cable to the monitor. While playing on the laptop, without connecting to the monitor, WoW seems to work fine, I don’t get any spikes in latency and my internet connection is great, I average 50-60ms probably. However, when I play WoW whilst connected to my monitor, the instances I load into occasionally have extremely high world latency. So, there is a high chance that the game becomes unplayable while going into dungeons, battlegrounds or just simply logging into open world due to the world latency being at around 4000 or 5000. Yet, this only happens if I’m playing wow whilst being connected to the monitor. I would really appreciate some help because I am scared of doing m+ or even raids due to the possibility that the game will become unplayable soon as I go into the instance.

Thank you in advance.