I don't know how to report this issue, but I'm facing real dead slow response after upgrading to 3.8.8.

Steps to reproduce the issue

Because we already have a lot of data in VM...
but you can install
Joomla-3.8.2 first
And install VirtueMart-3.2.8..
and a lot of data in VM
now upgrade to 3.8.7
and upgrade to 3.8.8

Expected result

Website should begin loading page right after pressed "Refreshed button" or clicked on any "link" ... and it should take as long as it need when downloading..

Actual result

When pressed "Refresh button" or hit enter after typing URL.. it takes 10s of seconds in connecting even on localhost and then starts loading.

System information (as much as possible)

PHP Version 5.6.10
System Darwin Muhammads-MacBook-Pro.local 17.5.0 Darwin Kernel Version 17.5.0: Mon Mar 5 22:24:32 PST 2018; root:xnu-4570.51.1~1/RELEASE_X86_64 x86_64
Server API Apache 2.0 Handler
Using MAMP Pro
Macbook Pro- 10GBRAM 128GBSSD 2.3GhzCi5

Additional comments

We are using virtuemart 3.2.8. We've been already facing slowing issue for many days after upgrading from j1.5 to j3.x. For a month around I've been debugging and trying to fix the slowing issue, but was not able to get fastest response.. but still by disabling many of modules, I had achieved good enough response.

I didn't touch the last update 3.8.7 before... but after updating to 3.8.7 around 5 days back .. there was no any big change... the response time when I used to "click" on any link or starting loading page after pressing "refresh button" waiting time was around 3, 4 seconds.. while that should start responding in a second. When I hit "refresh" in Backend (Administrator view), that works fine.

Now just around 30 minutes back.. I updated to 3.8.8.... now when I press "refresh button" or "enter" on URL that is taking more then 10 seconds.. But on the Admin view, it's working fine.

You may be saying that this is a VirtueMart issue, but this is the same VirtueMart with 3.8.7 or before.. I don't think this should be now all in sudden a VirtueMart issue?.