4 month old male cavoodle suddenly won't go on walks after encountering dirtbikes, advice?

Hey all,

Got a odd situation happening with our 4 month old amd am after some advice. We've started taking him on what we call 'big walks' - we live in a gated complex and don't have a super big yard, so we wanted to help get the extra energy out by taking him for about a 1km walk 2 times a day. At first he was super keen and loved it, but on our third walk we had an unfortunate incident involving some inconsiderate teenagers on non-electric dirtbikes who braked into u-turns a little too close to him and scared him quite badly. We had pulled off to the side of the footpath to avoid them.

We obviously took a short break from walks after that and reduced the distance, took a different route. No more incidents, but after another week of normal, short, safe walks he's started refusing to go. We get to the end of the complex but he wants to go straight back home before we can make it out of the gate.

Wondering if anyone's faced anything similar and if anyone has any tips to help us get out of this rut? We've tried bribery with treats, toys, different times of the day, myself and my fiance together and one of us at a time, but nothing really seems to help.