hEX PoE not working within an hour

RouterOS Beginner Basics
1

I ordered a hEX PoE on Amazon and it arrived today.
I unpacked it immediately and did some setup.
I had set up PPPoE and was looking for IPoE. I was curious if there is any update so I went to the Setting->Packages to see if there is any update.
I noticed there are some new versions, but I didn’t upgrade it.
Suddenly, the network is gone, and I refreshed my routerOS page it is no longer able to access.
I found many solutions, but still not able to access 192.168.88.1.
I tried reset the router, using netinstaller to install routerOS 7.11.2 and 6.49.10 (it shows installed successfully, and it rebooted automaticlly).

I used it no longer than an hour, but I just cannot access 192.168.88.1 again, and the network is not able use through the router.
I really want to know how can I solve it.

2

I unpacked it immediately and did some setup.
Suddenly, the network is gone, and I refreshed my routerOS page it is no longer able to access.

Sometimes the effects of a change are only seen later, because the current connection is still valid, and some paths are cached. (Ip route cache, 5 minutes delay for DHCP renewal, etc etc …)

Seems like you locked yourselves out for now.
Hint: use another ethernet port to connect (Port1 is usually a WAN port, denying remote access)
Use WinBox in discover mode (click Neighbors) and if the hEX PoE appears try to access via the MAC address (you can enter even if the IP configuration is not correctly setup