Hey there @zjk7648! Welcome to the community! This issue can be caused by a myriad of things. Though some users haven’t been able to solve it and this is a commonly reported issue with 5.3.2.
If using a VPN that you are able to disable, try this first as the content delivery for the plugin seems to struggle with some providers.
Allowing bridge through your firewall can help.
Signing out of the plugin and signing back in sometimes corrects the issue.