Using robust standard errors in random effects panel regression messes up chi²-value

[Fernando Lopez]

I am working on a random effects panel data regression with 400 observations and 70 groups, i tried using robust standard errors for comparison and whenever i use them the Prob>chi² around tenfold. Now im looking for guidance as to what might be causing this issue and also if there is a test to check if robust standard errors are preferable for the random effects model.