Edit:
By watching at this
View attachment 16546
I think it is your VPS/Connection.
It took (randomly) about 900ms to download a 80kb file and I do have 100MB/s Connection.
Like I said here, the internet connection is most probably the problem here. Maybe your Hoster "over-sold" his network.
Is this affecting all Websites installed on this Server?
If you do have another Server, can you try top move the Website and Domain to the other Server and try if the same issue appears on another Server?
You also use PHP 7.0, pls change to the newest supported version. But as you are on Wordpress 5.3.2 PHP 7.4 is recommended for best performance
Thx for your time. I think is the just the vps.
Its totally random the TTFB, now i have 50-100, sometimes 500, and something suddenly 6.5s.
I installed 7.0, because i was desperate. But yes i will go to 7.4
And yes all the websites have the same symptoms
I have 100mb/s connection and yes, sometimes i watched "Content download" 1 second.
When i am in ssh and i write "yum update" these days are like, slow, you know? I remember other days when i write "yum update" its like a flash, the console write so fast.
Thx