How to fix Slack not loading new messages in Safari after upgrading Mac to Monterey?

I use Slack in Safari browser to save memory usage and indirectly reduce battery usage from Slack. Slack in Safari browser used to display notifications and load new messages automatically till macOS got upgraded to Monterey 12.2.1. Now in macOS Monterey, the Slack web in Safari browser always displays Load new messages alert. Also, the notifications from Slack in Safari are not received. I tried to find solutions in many forums and communities, but of no use. Can anyone please help me with the solution for this? How to make Slack in Safari to show notifications and automatically load new messages?