Very slow response after new installation of ISPCONFIG in ubuntu20.04

This is the error I get frequently on most requests.
failed to load response data. no data found for resource with given identifier.
this happens every where even when I am trying to change the tab.
what could be the reason for this and resolution for the same.

 

this is what I get in browser console, just when I was trying to filter in clients page/tab
where else you want me to check.

 

not sure - but I am adding further info if that helps.
I was trying to add a test a client. after adding information in the client detail page I clicked on the limits tab.
the spinners shows for some time then went away, but the UI was not changed to limits tab.
in the browser console I can see the server url as - https://server1.myserver.com:8080/client/client_edit.php
and request as

Code:

ompany_name:
test
gender:
f
contact_firstname:
test
contact_name:
test
customer_no:
C165
customer_no_org:
C1
username:
test1
password:
Mc4J_HaPhyr7
repeat_password:
Mc4J_HaPhyr7
language:
en
usertheme:
default
street:
zip:
city:
state:
country:
IN
telephone:
mobile:
fax:
email:
[email protected]
internet:
https://
icq:
vat_id:
company_id:
bank_account_owner:
bank_account_number:
bank_code:
bank_name:
bank_account_iban:
bank_account_swift:
paypal_email:
added_date:
2022-12-04
added_by:
admin
notes:
id:
_csrf_id:
client_db3afc8e3e61642051f2f10b
_csrf_key:
4683a09c179b7b50dc98e5e012c1705d395833a8
next_tab:
limits
phpsessid:
a6bnomtsae79l2ddi5sicpr1b0

but in the response it says -

 

Hi Till,

if that is the case, then it shouldn't work at all I believe.
but it works sometimes and fails sometimes.

 

Hi Till,
I think you are quite right. actually there are packet drops between my machine and server.