There are many factors which depict that a project is scam -

1) Their telegram gets abandoned or the admins leave the group
2) their websie stops working and the server goes down
3) The coins/tokens get transferered form the projects' address to an exchange to dump everything
4) They stop posting on their social media and stop goiving more updates.
5) Your questions do not get answered by the admins
6) BitcoinTalk stops getting replies and stops getting updated.

and much more, bsaically the team does not considers the project and do not work more , most probably the project dies.
If you try to talk to the team in linkedin then they do not reply your messages.