__lll_lock_wait allowing only one thread to work

Quick update, I wasn't setting the XPRS_THREADS to 1, now I am doing it like this:

XPRSsetintcontrol(pxprs, XPRS_THREADS, 1);

The value of XPRS_THREADS being set is 8278:

But I appear to have broken something as I am getting this written to the log (this is a log for a specific XPRSmipoptimize for a specific thread, i.e. no output from mixed sources):

Reading Problem MipSimplex
Problem Statistics
          33 (      0 spare) rows
         162 (      0 spare) structural columns
         251 (      0 spare) non-zero elements
MIP Entity Statistics
           5 entities        0 sets        0 set members
FICO Xpress v9.0.2, Hyper, solve started 10:11:31, Apr 13, 2023
Heap usage: 185KB (peak 2946KB, 70MB system)
Maximizing MILP MipSimplex using 1 thread and up to 125GB memory, with these control settings:
THREADS = 1
Original problem has:
        33 rows          162 cols          251 elements         5 entities
Presolved problem has:
        17 rows           80 cols          113 elements         4 entities
Presolve finished in 0 seconds
Heap usage: 233KB (peak 2946KB, 70MB system)
 
Coefficient range                    original                 solved
  Coefficients   [min,max] : [ 1.12e-02,  1.43e+02] / [ 6.25e-02,  2.00e+00]
  RHS and bounds [min,max] : [ 4.37e-10,  8.21e+07] / [ 7.66e-02,  1.18e+03]
  Objective      [min,max] : [ 1.00e-02,  1.29e+05] / [ 1.00e-02,  4.30e+05]
Autoscaling applied standard scaling
 
?9999 Error: Unexpected system error (code 24) while Opening /proc/meminfo
?9999 Error: An error occurred within the Xpress solver (RETURN_STATUS_UNKNOWN)
 *** Search unfinished ***    Time:     0.03 Nodes:          0
  Solution time / primaldual integral :      0.03s/ 100.000000%
  Number of solutions found / nodes   :         0 /         0

(Note the log showing THREADS set to 1)

I will be looking into it.

Thank you!