I have the same issue... I managed to workaround it by DISABLING the chrome-pool, e.g. remove
"chrome-pdf": {
"strategy": "chrome-pool",
"numberOfWorkers": 3
}
from the config. It works.
It is pity as chrome-pool works perfect when using directly in Kestrel (starting from cmd with dotnet Whatever.dll). It also works on my developer machine under IIS Express, but when I publish it to a staging IIS 10 / Windows Server it constantly gives timeouts :(.
Anyway sticking on the default, which starts "extra new chrome process every time you render a template" makes it work, on the price of slower execution.