Understanding the Differences between MIP and RMIP Solvers

Hi all, I would like to seek clarification regarding the disparities between MIP (Mixed Integer Programming) and RMIP (Relaxed Mixed Integer Programming) solvers. While I understand that RMIP converts integer variables into continuous variables, I would like to explore any other significant dissimilarities between these two solvers.

Specifically, I am encountering fluctuations in the results of one of the variables when utilizing the MIP model as shown in the picture below. Despite the absence of any constraint-related issues, the values exhibit variability instead of remaining constant. 

Conversely, when employing the RMIP solver, the values remain consistent throughout (as presented in picture below). 

I am keen to understand the cause behind these fluctuations and any significant disparities between the MIP and RMIP solvers that could potentially explain this behavior. Any insights, explanations, or suggestions on how to address these fluctuations would be greatly appreciated too! 

Thank you in advance for your assistance!