Nextcloud Client Ubuntu always upload entire files

Hi Nextcloud team and users,

I’ve been using Nextcloud (NC) for almost 3 years now, migrated from OC. We run NC in the cloud and share all folders through a master user. So this user is holding all files and folders, and share those files to some users with specific permissions. So far so good, until a user who uses Ubuntu always complaint that the NC client always upload the entire files that he got from another computer everytime his laptop started. He has 3 other computers and those computers sync the same files and folders to the NC server. Those 3 computers are Windows, Linux Mint, and MacOS. The Windows and Linux Mint are using the same folder shared between operating system on dual boot PC and it works perfectly. MacOS is another separate setup. The Ubuntu is in another separate laptop.
He said the NC client installed using the ppa nextcloud-dev repository.
What makes this Ubuntu NC client different than in Linux Mint?

Thank you and regards