Answer to MacBook Pro beeping every 5 seconds after being shut down.

Only found this from Apple Support If your Mac beeps during startup - Apple Support

But 5 beeps I only found in other websites saying something wrong with CPU. Not sure how to deal with it. Didn't find any good answers for this.

https://www.seagate.com/br/pt/support/kb/macintosh-beep-codes-185311en/

https://discussions.apple.com/thread/5221190

https://forums.macrumors.com/threads/constantly-beeping-macbook.622161/

Try these procedures and test again the sequence that raised the issue for you

How to reset the SMC of your Mac - Apple Support

Reset NVRAM or PRAM on your Mac - Apple Support

Have you tried plugging the charger into the same USB-C port that the hub used to make sure that particular port works properly with the charger connected directly to the laptop. These USB-C ports can be difficult to troubleshoot because they may work perfectly fine with data transfers but not work for the charger (or vice versa). Even rotating the USB-C connector on the cable 180 degrees upside down can cause the item to work/fail indicating the USB-C port is half bad.

Make sure to only use good quality accessories & peripherals from well respected and trusted manufacturers. Low quality products can easily cause problems on a Mac if not even causing damage to the Logic Board (expensive repair). It is best if you use devices that specifically mention Apple compatibility as well since Apple products work differently than most other computers and are much pickier about things.

I have personally seen even Apple's own multi-port adapter prevent the full power of the charger from reaching the laptop (although they never produced the repeated "dinging"). These USB-C adapters & docks don't always work like we think they do.

If you have an Intel Mac you can try performing an SMC Reset, but I don't expect this to help.

@Rafael Scheid, I think the beeping the OP mentions is the "ding" the laptop makes when connecting a charger.

I think it’s the situation HWTech pointed out, the hub is not transfering power properly to the Mac and it keeps beeping because it’s switching on and off charging.