Issues with seed setting in parallelised foreach loop R

Question

I have a selection of tests I want to run in parallel. When I do this using foreach(), I get the expected output of 20 test - iteration pairs:

## Without seed
require(data.table)
require(foreach)
require(iterators)
require(doParallel)
require(doRNG)

numCores = 2
registerDoParallel(numCores)

iterations = 5
num_tests = 2:5

foreach( i = 1:iterations, .combine = 'rbind', .multicombine = TRUE, .inorder = FALSE ) %:%
  foreach( n = num_tests, .combine = 'rbind', .multicombine = TRUE, .inorder = FALSE ) %dopar% {
    
    ## Print iteration
    print(paste('Tests =',n,'Iteration =',i))
    
  }

Output:

result.1 "Tests = 2 Iteration = 1"
result.2 "Tests = 3 Iteration = 1"
result.3 "Tests = 4 Iteration = 1"
result.4 "Tests = 5 Iteration = 1"
result.1 "Tests = 2 Iteration = 2"
result.2 "Tests = 3 Iteration = 2"
result.3 "Tests = 4 Iteration = 2"
result.4 "Tests = 5 Iteration = 2"
result.1 "Tests = 2 Iteration = 3"
result.2 "Tests = 3 Iteration = 3"
result.3 "Tests = 4 Iteration = 3"
result.4 "Tests = 5 Iteration = 3"
result.1 "Tests = 2 Iteration = 4"
result.2 "Tests = 3 Iteration = 4"
result.3 "Tests = 4 Iteration = 4"
result.4 "Tests = 5 Iteration = 4"
result.1 "Tests = 2 Iteration = 5"
result.2 "Tests = 3 Iteration = 5"
result.3 "Tests = 4 Iteration = 5"
result.4 "Tests = 5 Iteration = 5"

However, when I attempt to add a step to this loop that sets a random seed as described in the doRNG vignette, I get a different number of tests per iteration (14 test-iteration pairs):

## With seed
numCores = 2
registerDoParallel(numCores)

iterations = 5
num_tests = 2:5
rng <- RNGseq( iterations * (iterations+1) / 2, 1234)

foreach( i = 1:iterations, .combine = 'rbind', .multicombine = TRUE, .inorder = FALSE ) %:%
  foreach( n = num_tests, r = rng[(i-1)*i/2 + 1:i], .combine = 'rbind', .multicombine = TRUE, .inorder = FALSE ) %dopar% {
    
    ##Set seed
    rngtools::setRNG(r)
    
    ## Print iteration
    print(paste('Tests =',n,'Iteration =',i))
    
  }

Output:

result.1 "Tests = 2 Iteration = 1"
result.1 "Tests = 2 Iteration = 2"
result.2 "Tests = 3 Iteration = 2"
result.1 "Tests = 2 Iteration = 3"
result.2 "Tests = 3 Iteration = 3"
result.3 "Tests = 4 Iteration = 3"
result.1 "Tests = 2 Iteration = 4"
result.2 "Tests = 3 Iteration = 4"
result.3 "Tests = 4 Iteration = 4"
result.4 "Tests = 5 Iteration = 4"
result.1 "Tests = 2 Iteration = 5"
result.2 "Tests = 3 Iteration = 5"
result.3 "Tests = 4 Iteration = 5"
result.4 "Tests = 5 Iteration = 5"

I'm looking for a way to set seeds in parallel, nested foreach() loops with the correct number of iterations. Any ideas?