Somewhere in the Huawei's admin page will be DHCP settings. The range of addresses that it uses will be fixed & documented in the manual or user configurable. The DHCP "range" is the addresses that it will hand out automatically to devices as they connect. There needs to be another range of addresses that aren't handed out & can be used for static addresses, like you need to give the HH4.
What is the model no. of the Huawei?
B525
Unfortunately the user manual is about as useful as an ashtray on a motorbike.
As above, manual seems to be just a Quick Start. Given that your PC acquired an address of .159, it would be reasonable to assume that the DHCP range is in the higher numbers. I'd try resetting the HH4 to 192.168.8.2 as that should be outside the DHCP range.
If that doesn't work you're going to need to seek help on a forum that specialises in that model. I seem to recall there are many different versions & some may be locked down, depending on where they came from. See this thread.
Not sure if this any help on DHCP ip range on Huawei is 192.168.8.100 - 200
Ok will try that ip address thank you for your help
In that case your .66 should be fine. In which case refer back to my previous post of what to do next.
Just a thought but does the Huawei admin page show a list of connected devices? If so have a look & see if anything is connected to an address below 100 or above 200. If there is, that will be the address of the HH4.