I had booked two tickets for Family members. Outbound flight last year. Return Flights cancelled during the first lockdown. Both rebooked online to a date beyond 1 year.
Wanted to change one to bring it earlier, was told no. Was told Online Error should not have happened. The Rebooked flight was cancelled and the first Agent I spoke to reissued the ticket.
So not a System Restriction.
Second ticket, nephew wanted to change to a travel few days early. Just told him to keep to it as was not sure whether they will do it or not.