From my experience a lot of people will not hesitate to contact you via WhatsApp even in a professional setting if they can get hold of your phone number. After this happened several times to me I made sure to have a separate phone for business where no messengers or any "social" apps are installed. The funny side of this behavior is your client messaging you via WhatsApp but forgetting their profile picture shows th…
I’ve never understood the appeal of WhatsApp: it requires a phone number (so it’s useless or hard to setup abroad, and it’s tied to a very personal data), handle very poorly wifi connection (somehow it seems to only update when connected over 4G) and force me to download pictures and videos to see them, trashing my photo folder in the process. It also has no killer features in comparison to any existing messaging app…
There is option in Chats\media visibility to not trash your photo folder
not sure what are you using what is safer and/or does not require phone number