With the 2.8.0 there is a default timeout 60s.
You can see it in the output
2020-11-09T11:35:23.926Z - info: Using general timeout for rendering (reportTimeout: 60000)
If you want to increase it, you can use the environment variable
docker run -p 5488:5488 -e reportTimeout=120000 jsreport/jsreport:2.8.0
When you are still getting the timeout afterward, you may be hitting one bug we fixed recently. You can try to install the patch using
npm i jsreport-html-to-xlsx@2.8.1 --save