@Toufiq : I had a call with current host provider and they told me this.
could you have a look on your side?
I don't know how joomla works at this level but nothing happens when I click the button immediately.
I made a "strace" of the PHP process which is launched and when I click on the button, no PHP action is launched for at least 15 seconds.
When I click on the button, in the web logs, nothing happens either and I get a "POST" request 15 seconds later:
mywebsite.com - - 10.20.0.20 - 56570 - - [13/Apr/2023:09:13:45 +0200] "POST /index.php?option=com_sppagebuilder&task=page.apply&pageId=7 HTTP/2.0" 200 162 225068 279 443 "https://mywebsite.com/edit/7.html" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/111.0.0.0 Safari/537.36" req_time=30.654 upstr=109.234.164.140:4430 up_co_time=0.003 up_resp_time=30.654 o2s-chl=297c668fcd0aa9385df78c1446766877 wl=0
For me, there is something on the website side that causes this to produce a particular latency but it is not coming from the server. The server does not receive any PHP request/processing for 15 seconds.
It could have been a PHP processing delay when pressing the button.
If the problem came from the server, I will have logs in the strace immediately after pressing the button and above all, I will have a trace in the web logs immediately after pressing the button which is not the case .