Learn English – Difference between have been + ing and ed

"have been" is past participle so you would use past tense "associated". "am" is present participle so you would use present tense "associating".

If you are telling a story it helps to use -ing verbs if you can tell it in the present tense it takes the reader on the ride with you and they can feel like they are more there with you because it is happening as they read not has happened in the past but you should stay consistent with your tense so the story makes sense not jumping from past to present to future.

You would NOT say "I have been associating with GRM." You could say "I was associated with GRM." If you "have been" then you aren't "-ing" now, by using a past participle with a present tense you are implying a past action not a present one. Therefore, you take the reader on the journey but you do not imply a present action which presents a context in which you might find useful if you want to pose to the reader the question "Are you associating with GRM now?"

If you "are or am" then you are "-ing" not in the past but currently. And if you "haven't been, "are" or "am not" but in the future "may be" then you "will be" associating ;)

https://www.ecenglish.com/learnenglish/lessons/simple-tenses-verbs