DIAGNOSIS Yeah, this one's common. An Archer AXE75 rebooting on its own is almost always a heat or power supply issue. These routers put out a lot of wireless signal and the chipsets can get warm. If it's in an enclosed space or on top of another hot device, it'll overheat and reboot to protect itself.
FIX First, check its location. Move it to an open, ventilated area, not tucked in a media cabinet or on a carpet. Ensure all vents are clear. Unplug the power adapter from the wall and from the router, and reseat both ends firmly. Try plugging the adapter directly into a wall outlet, not a power strip or surge protector that might be failing.
IF THAT DIDN'T WORK The issue could be firmware-related. Log in and check your current firmware version under Advanced > System Tools > Firmware Upgrade. Compare it to the latest version listed on the TP-Link support site for the AXE75. If you're behind, upload and install the latest firmware. A bad firmware update can sometimes cause this too, so a factory reset after updating might be necessary.
HEADS UP Never use a third-party or higher-wattage power adapter. The AXE75 needs 12V and 2.5A specifically. Using a different one can cause unstable voltage and trigger reboots, or worse, damage the router.