Where is the relative gap from cplexbilp?

I am invoking "cplexbilp" (CPLEX 12.9) from Matlab R2022a. I request all 4 return arguments:

[x,fval,exitflag,output] = cplexbilp(...)

I use the variable browser to browse the 4 outputs. Nowhere is there a relative gap. I set the options to terminate at a relative gap of 1e-4 (0.01%), but I'd like to know what the actual relative gap is. I know that for lengthy enough searches, the display console will show periodic updates, but my problem is solved immediately (albeit with "numerical issues"). Will "numerical issues" prevent the appearance of a relative gap in (say) the "output" argument above?

If the relative gap simply isn't available, but if I can get the numerical best-bound (as unlikely as that might sound), I can calculate the relative gap.

P.S. I initially posted this to a the following page, but it occurred to me that this might be a limitation of the Matlab/CPLEX interface:

https://or.stackexchange.com/questions/8653/where-is-the-relative-gap-from-cplexbilp