Hlt2Conf.test_hlt2_trackefflines assert fail in TrackMasterFitter::initializeRefStates

An assert has failed in Hlt2Conf.test_hlt2_trackefflines in a ci-test in !1095 (comment 5256687) . This is reproducible in other tests including on master, but well hidden by a timeout.

../Event/TrackEvent/src/Track_v1.cpp:199: void LHCb::Event::v1::Track::addToStates(gsl::span<LHCb::State* const>, LHCb::Tag::State::AssumeSorted_tag): Assertion `with_order( useDecreasingOrder{checkFlag( Track::Flags::Backward )}, [&]( auto order ) { return std::is_sorted( states.begin(), states.end(), order ); } ) && "states are not correctly sorted;" "hint: use the general addToStates function assuming unordered states"' failed.

#11 0x00007fa28eeeb387 in raise () from /lib64/libc.so.6
#12 0x00007fa28eeeca78 in abort () from /lib64/libc.so.6
#13 0x00007fa28eee41a6 in __assert_fail_base () from /lib64/libc.so.6
#14 0x00007fa28eee4252 in __assert_fail () from /lib64/libc.so.6
#15 0x00007fa269881f9a in LHCb::Event::v1::Track::addToStates (this=this
entry=0x7fa2316faef0, states=...) at ../Event/TrackEvent/src/Track_v1.cpp:199
#16 0x00007fa261e04ba8 in TrackMasterFitter::initializeRefStates (this=this
entry=0x9a5b3500, track=..., geometry=..., pid=..., pid
entry=...) at ../Tr/TrackFitter/src/TrackMasterFitter.cpp:908
#17 0x00007fa261e04cda in TrackMasterFitter::makeNodes (this=this
entry=0x9a5b3500, track=..., pid=pid
entry=..., accelCache=..., geometry=...) at ../Tr/TrackFitter/src/TrackMasterFitter.cpp:572
#18 0x00007fa261e05730 in TrackMasterFitter::fit_r (this=this
entry=0x9a5b3500, track=..., accelCache=..., geometry=..., pid=...) at ../Tr/TrackFitter/src/TrackMasterFitter.cpp:195
#19 0x00007fa261e06a25 in TrackMasterFitter::operator() (this=0x9a5b3500, track=..., geometry=..., pid=...) at ../Tr/TrackFitter/src/TrackMasterFitter.cpp:169
#20 0x00007fa262aff354 in SeedMuonBuilder::operator() (this=this
entry=0x9861c7c0, muontracks=..., scifitracks=..., lhcb=...) at ../Tr/TrackTools/src/SeedMuonBuilder.cpp:108

Also reported in LHCb!3226 (comment 5181213)

/cc @decianm