How to lock or remove recovery options on an Android phone, specifically UleFone Armour X7 Pro?

At work, we have the Ulefone Armor X7 Pro to log activities and time. It is locked down by Hexnode for Work, but I was initially easily able to circumvent a lot of this by force-restating the phone (power off has been disabled), and when it starts up again, quickly open settings from the drop-down menu. Once the Settings app is open, Hexnode didn't block it. Through that, I was able to find the WiFi password of the company. I told my manager about this vulnerability and he fixed my access to settings by disabling the dropdown menu with Hexnode. He also disabled the power button in Hexnode, but it doesn't really disable the button, rather, it just turned back on the screen if I put the phone to sleep. This drained everybody's battery and was no fix because I could still force restart it. Our IT guy seems to have no fix for this problem. Does anybody know how I could block the restart option with some kind of code?