In an issue reminiscent of Apple's iPhone 4 'Antennagate' woes, it appears that Samsung's flashy new Galaxy Tab S5e is suffering from Wi-Fi signal attenuation issues when users place their hand in a certain position on the device. The problem is repeatable and has been encountered by several users according to SamMobile.
https://www.notebookcheck.net/Samsung-Galaxy-Tab-S5e-users-report-Wi-Fi-related-hardware-concerns.419996.0.html