Error in iterative mode

[AllenIsaacJose]

The error occurs for every iteration in the iterative method using ISAM2()

Indeterminant linear system detected while working near variable
8142508126285856768 (Symbol: q0).

Thrown when a linear system is ill-posed.  The most common cause for this
error is having underconstrained variables.  Mathematically, the system is
underdetermined.  See the GTSAM Doxygen documentation at
http://borg.cc.gatech.edu/ on gtsam::IndeterminantLinearSystemException for
more information

[AllenIsaacJose]

If I change the iterative mode from every iteration to once every 6 iterations(I had 5 objects), then the error will appear away as it has enough observations. But the s.estimates = s.optimiser.calculateEstimate() step after that will create estimates for the dual quadrics and camera pose with very high error and won't give any proper results after that.