bartMachine serialize compatibility between CPUs

Question

When using bartMachine, if I create the bart model on one machine with serialize = TRUE

bart <- bartMachine(X, Y, 
                    k = 2,
                    num_trees = 50, 
                    use_missing_data = TRUE,
                    serialize = TRUE,
                    verbose = FALSE)

and save it (save(bart, file = 'bart.bartmachine')), I cannot open it on a different machine (load(file = 'bart.bartmachine')), receiving the error:

Error in check_serialization(bart_machine) : 
  This bartMachine object was loaded from an R image but was not serialized.
  Please build bartMachine using the option "serialize = TRUE" next time.

This is consistent in both directions:

• Create and Save on Machine 1 -> load on Machine 2
• Create and Save on Machine 2 -> load on Machine 1

I have the seed set and cores set to 1:

set.seed(123)
set_bart_machine_num_cores(1)

Any thoughts on how to make this compatible? I could work around by saving machine specific versions but trying to avoid this.