WhatsApp integration works for some users but not for others

We're using a Pro plan.
We created a flow which is connected to WhatsApp. The app is in Live mode on Facebook. I've tested the token I supplied to Typebot making direct requests to the api and it works; i've tested the Whatsapp webhooks setup and it is working fine.

Some ten users have tested the flow from Whatsapp. For half of them the flow worked fine. For the other half the bot doesn't respond. Any insights on what might be the cause? Can we check Typebot logs?