Same issue here. I cannot see private messages (I see that I got one but there is no button/image/text to click on to read it), here my findings:
login out/in -- doesn't help,
Clearing cash and login in again -- doesn't help
Using different browser -- doesn't help
Using phone instead of a laptop -- doesn't help
I still can't see messages here but since the website chat isn't available despite business hours I went on facebook messenger and someone there was able to help me.