I know this isn’t exactly the most important bug but the larger the group, the greater the discrepancy.
The way group members are rounded for the Roblox profile is different to the way they’re rounded on the groups page.
In the case presented below (the Roblox group) the accurate group member count was 1,523,852. I would expect this number to either be presented as 1.5M+ or 1M+ as 2M+ is a bit misleading.
At present, it is shown as 2M+ on a user’s profile, and 1M+ on the group page itself.