Integer infeasible in vehicle routing prolem model

[irem]

Hello GAMS Experts,

I am currently working on a vehicle routing problem. I am still not very proficient with GAMS. The model's output gives an "integer infeasible" message, and the root cause seems to be the "alfa" and "beta" variables. However, I attempted to manually construct the model on a small scale, yet I couldn't find a solution. I am sharing the code in the attachment. This is crucial for me. I would appreciate it if you could assist.

Error Message: Infeasible column 'alfa(1.3.1)'

Additional information: Sub-tour constraints exist between 'cons10 - cons16'. The problem originates from 'cons3' and 'cons5'.