Please report both positive and negative results.
A previously afftected Aures nino POS-terminal boots just fine with CentOS 7 and shim 15.8.
Now I will test an affected machine (Aures Twist POS terminal) that runs CentOS 8 (well, usually runs CentOS 8, but not now, since it does not boot ... :=>
The affected machine running CentOS 8 boots fine after upgrading to shim 15.15
Thanks for acting quickly, especially on a weekend.