Who were you trying to contact and what serial number was needed? Motherboard or RAM?
It is hard to say. I am just trying to eliminate RAM MEMORY being incompatible or not fully compatible with your Rzyen processor.
Have you tried installing the latest Ryzen AMD Driver for your APU and see if it makes any difference using DDU?
Which Asus support did you try? the USA or Brazilian Support?
If you tried the USA ASUS Support then try with the Brazilian ASUS Support since that is a Brazilian Asus motherboard.
I read that the motherboard should have a sticker on it:
Make sure you copied it correctly. Sometimes Number "0" looks like the letter "o" and vice versa. or Number "1" look like the letter "l".
No need to. Just letting you know because that happened to me once on a hardware I was registering at a Support site. I mistook the letter O for a the number 0.
You are correct. That is the correct serial number. I inputted your Asus Motherboard S/N at Asus Warranty site and it came up to be good: Official Support | ASUS USA
I recently got the same Processor and Motherboard as you and had the same problems as well. The only "workaround" I've found so far is to deactivate the Clock Boost feature in the BIOS.
Enter the BIOS then press F7 and go under Advanced > AMD CBS > and set Core/Clock Boost to Disabled.
I have the same issue with almost the same setup and that did not solve my issue. One thing to note, when the freezing happens my network connection will become disabled. If I'm playing a video from Youtube it will continue playing until the buffer runs out but the keyboard/mouse do not respond and my only option is to reboot the computer by physically pressing reset.