Edocman search error 504

Hello,
I'm using Joomla 5.4.1.

I installed Edocman version 3.2.

(For your information, I had to disable the slider plugin because otherwise nothing was displayed on the site and I got the error:
"Call to a member function getString() on null")

But my problem now is that when I perform a first search using the Edocman Search module, it works the first time, but after that, all searches time out (error 504).

I've increased the PHP server memory to 256MB.

And if I reindex the searches from the administration panel, the first search works again, but only the first time.

Do you have any idea what the problem might be?

Hi,
This issue seems to be quite serious and may require a thorough investigation.
Please create a support ticket in the Edocman category and provide your site information along with an administrator account. This will allow me to access your site and look into the problem in detail.
Thank you for your cooperation.
Best regards,
Dam