i have the following problem, chrome or chromedriver stops working after 30min

I have been working with the Selenium Framework in combination with chromedriver and chrome for a while now. I already have a lot of experience with it.
I have not been able to solve one problem so far, or rather I have tested all the options I have found on the net. unfortunately in vain.

with the following scenario, selenium or chromedriver or chrome stops working:

1. i navigate to a url with “Navigate(…)”
2. on this page only javascript functions with ajax requests are addressed
3. after 30min the currently used instance no longer reacts to actions via selenium
4. only after a new “Navigate(…)” to a url or a siterefresh does the page react via the selenium actions

Because of this circumstance, longer-running tests on the website can never be completed, as the current status is destroyed by a siterefresh.

I have not yet been able to find out which of these 3 components is causing the problem. i think it is some kind of timeout or something similar. however, i have tested all timeout settings without success.

the instances are fine, none of the components crashes. only a new url navigate solves the problem.
the selenium instance reports after 30min, that the current element is no more clickable. the element is not null at this time.