Weird infeasibility listing

Hi everyone,

Today I was running my energy model and I faced this weird infeasibility in the listing file: 

balance_activities(Houses - Residential Terrace,2050) ..

    + 1 * tech_use(Res03_01,2050) + 1 * tech_use(Res03_02,2050) + 1 * tech_use(Res03_03,2050) + 1 * tech_use(Res03_04,2050)
    + 1 * tech_use(Res03_05,2050) >= 4060 ;  ****

    name                      lower   upper
    tech_use(Res03_01,2050)   0       0
    tech_use(Res03_02,2050)   0       0
    tech_use(Res03_03,2050)   0       0
    tech_use(Res03_04,2050)   0       0
    tech_use(Res03_05,2050)   0       4060.000 

It seems the upper bound of tech_use(Res03_05,2050) is respecting the mentioned constraint as 4060.000 is larger than 4060. Do you have any idea why AIMMS arises this ifeasibility?

Thank you in advance.