So I have been checking newegg every once and awhile to see if they are any new AM4 Boards and there is something wrong with their search. One quick example is if you go to mobo/amd/ and then put in AM4 mATX and it doesnt show any x370 boards yet there is 1 currently available on their site.
Just super weird and didn't know if anyone else had been experiencing issue on their site.
ive found that clearing my cookies (chrome- settings, advanced, content settings, all cookies and site data, search for newegg and delete everything found), usually solves this problem.
I just did the same search and noticed the same thing. Then I noticed that it doesn't have AM4 listed for that motherboard in the title. I unchecked the AM4 search, leaving the AMD X370 filter and it appeared. It's just an issue with the listing filtering it out because it doesn't have the socket listed.