Back-track simulation not stopping

Summary

Back-tracking simulations worked fine for me with OPAL 2.4, but with OPAL 2021.1 they are not stopping anymore and go to infinity!

For example this input file used to work fine, and stop at s=0.0, but now it just goes forever slurm-120179.out.

ParallelTTracker {0}> 19:59:38 Step    999 at 5.887 [m], t= 19.637 [ns], E=44.457 [MeV]
ParallelTTracker {0}> 20:00:09 Step   1999 at 4.987 [m], t= 16.637 [ns], E=44.457 [MeV]
ParallelTTracker {0}> 20:00:41 Step   2999 at 4.088 [m], t= 13.637 [ns], E=44.458 [MeV]
ParallelTTracker {0}> 20:01:13 Step   3999 at 3.189 [m], t= 10.637 [ns], E=44.458 [MeV]
ParallelTTracker {0}> 20:01:46 Step   4999 at 2.289 [m], t= 7.637 [ns], E=44.458 [MeV]
ParallelTTracker {0}> 20:02:18 Step   5999 at 1.390 [m], t= 4.637 [ns], E=44.459 [MeV]
ParallelTTracker {0}> 20:02:50 Step   6999 at 490.765 [mm], t= 1.637 [ns], E=44.459 [MeV]
ParallelTTracker {0}> 20:03:23 Step   7999 at -93.005 [m], t= -1.363 [ns], E=44.460 [MeV]
ParallelTTracker {0}> 20:03:55 Step   8999 at -951.669 [m], t= -4.363 [ns], E=44.460 [MeV]
ParallelTTracker {0}> 20:04:27 Step   9999 at -2709.652 [m], t= -7.363 [ns], E=44.460 [MeV]
ParallelTTracker {0}> 20:05:00 Step  10999 at -5366.954 [m], t= -10.363 [ns], E=44.460 [MeV]
ParallelTTracker {0}> 20:05:32 Step  11999 at -8923.576 [m], t= -13.363 [ns], E=44.461 [MeV]
ParallelTTracker {0}> 20:06:04 Step  12999 at -13379.517 [m], t= -16.363 [ns], E=44.461 [MeV]
slurmstepd: error: *** JOB 120179 ON merlin-c-117 CANCELLED AT 2021-12-20T20:06:15 ***

I can't figure out why this is happening. When I have time I will check at which commit it broke, somewhere between 2.4 and 2021.1. Not sure if it is related to #675 (closed). Any ideas?