This rule:
{(<#:>|999|112|101|111|116000|116111|116123|1471|1571|100|155|195|0[38]xxxxxxxxx):li}
is only matching 08 numbers with eleven digits. In the UK some 08 numbers are ten digits and some even shorter. I'm guessing that if SP1 is your Primary Line and its digitmap contains a rule such as "xx.", then that rule is matching the shorter 08 numbers and sending them to VOIP.
To match ten and eleven digits:
{(<#:>|999|112|101|111|116000|116111|116123|1471|1571|100|155|195|0[38]xxxxxxxxx?):li}
To match any number of digits:
{(<#:>|999|112|101|111|116000|116111|116123|1471|1571|100|155|195|0[38]xx.S3):li}