What is the "advanced mode" on the HP50G???

In regards to the HP 50G program UtilsGCC V.11 by Gjermund Skailand, it
mentions in the documentation of an "advanced mode" when speaking of
the PROOT function as follows.....
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b) Example with "numerical" polynom

[1.  -12.6 72.15 -247.84 567.4575 -909.30918 1040.591233 -850.431318
486.424066 -185.44642 42.41233 -4.408211 ]
PRoot

-> Warning and no roots. Use "advanced mode" and try again.


{[1.  -12.6 72.15 -247.84 567.4575 -909.30918 1040.591233 -850.431318
486.424066 -185.44642 42.41233 -4.408211 ]
1000. 1000. 1000. }
PRoot
{[1.000000 -1.099996]
[1.000000 -2.299988 1.319987]
[1.000000 -2.300004 1.320004]
[1.000000 -2.299998 1.319998]
[1.000000 -2.300008 1.320010]
[1.000000 -2.300005 1.320006] }
[6 5 ]      ..multipicity structure
[1.100000 1.200000]  ..Roots

The exact polynom is (x-1.1)^6 * (z-1.2)^5

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What exactly is this "advanced mode" that is spoke of here?? Wht mode
changes does one do to make the PROOT example work??

I tried using and not using the "numeric" mode in the CAS mode choices,
but that has no effect.

Thanks
.