Python Discord bot running fine according to Render - but shows offline after a while in Discord. What is the Reason?

Hi everyone,

I ported my bot over to Render and deployed it successfully. It also runs fine and responds to request from discord quite a while after fresh deployments.

But sooner or later the bot is shown as offline in discord while in Render the service is still running fine (using keep_alive.py). What is the reason for this behaviour?

Any hints or help highly welcome!

Thank you in advance and
Kind Regards