I have experienced that sometimes too and from my experience I think it mostly happens when the forum traffic is way high. But sometimes the strength of our internet connection can also be a contributing factor.
I do not think it is either of these two reasons. I have been noticing it since morning since I woke up and till now. We can not say the forum is having higher traffic today than it is since may days or weeks ago when we are not seeing the issue. Also I am using 5G phone with good I testnet connect that is very fast and I am seeing the issue. Probably this will be something against DDOS attack is my guess and we will not see it again after some period of time.