Onload apex imperative method returns nothing in js constructor() but on second refresh it returns the proper data, why this is happening in LWC?

Question

I have called apex method in constructor() imperatively which returns the list of custom object...but when I initially load the LWC component it returns nothing but when I refresh again it returns the proper data, I also printed the data in apex before returning. On initial load of LWC Component it prints null but on second refresh it prints the proper data and returns to the LWC constructor(), how and why this is happening? Is it a bug or any loophole?

Please help to resolve the above issue. Thanks in advance.