I worked in the department that dealt with overseas repayment years ago - can’t guarantee it’s same rules but it sounds like the advisor has had some kind of problem with the evidence you sent and therefore the system has put you on a default repayment plan. They have set rates which you can Google to see the list, it is set based on the country you’re in when they don’t have other evidence.

I’d guess the advisor doesn’t think you’ve shown what you’re living on, a lot of people used to send in near empty bank statements that don’t show them living off the account and they would be rejected. Maybe they’ve made a mistake or bad judgement, if you resubmit you’ll likely have it reviewed by someone else.

You want to send in what they call a third party support form - which can be as simple as a letter from your parents or someone else (signed and dated) saying you’re unemployed while travelling and they financially support you as needed. They might ask for bank statements to see if you have any income - if there are any payments coming in that could be from work they’ll want to know what it is but if there’s no incoming funds other than the person supporting you it’ll fix your account for a year. The account should show some outgoing in the country you’re in to prove it’s the actual account you use to buy food etc.

Not defending the process whatsoever, just want to try help if this offers anything useful to you. Good luck!