How does foreign travel affect security vetting?

Additional information

I joined the army earlier this year, but I turned up to training with an injury and was discharged for defect in enlistment after a few weeks. I’m going to re-enlist because I really want to join the army, but I’m planning to take this opportunity to go travelling for a while before I do. I’ve been travelling before (I went backpacking through Europe and the Balkans after my A-levels), which I disclosed during the security check we did at the start of training (I think it was the CTC check, but I’m not entirely sure) and didn’t have any issues with it that I know of This time, I plan on backpacking through South America for roughly a year (specifically Colombia, Ecuador, Peru, Bolivia, Chile and Argentina). I won’t be staying in any of those countries longer than the 90-day visa-free entry allows, but I was wondering if travel to any of those countries could pose a risk to my re-enlistment and subsequent security and vetting checks once I return?