Please advise the database for .net (WPF). I implement a database for logisticians (plates 20 (carriers, city, logisticians, types of machines, etc.), about 30 users, the database is on the server, all are connected via client machines on LAN) It would be good to meet the following criteria: 1 - Multi-user 2 - Portable 3 Free
Implemented on SQLite + Entity framework. Everything works wonderfully, but only on one client, when connecting 2+, it starts terribly to slow down when accessing the database. I tried everything, I can not find a bottleneck. Now I think to implement on something else.
Perhaps I come from the wrong side, I ask for advice, I am self-taught myself. Thank you in advance!