Connecting to rstudio server from Mac OSx

Hi,
I have a studio server installed on an Ubuntu machine.
Lately, trying to reach it from my new laptop (Mac OS m3) I get an "connection not secured" error.
I'm trying to reach via port 8787 and the external IP of the computer (I'm within the same network).
I previously owned an Ubuntu laptop with no issues at all.
Any ideas?
Best,
Or