Does having a relatively low gpa (2.5-2.8) matter with research?

However, after first job it does not matter.

Not all jobs ask for GPA. It is not listed as requirement on job postings. So you maybe absolutely fine.

Dd got a job, also BME (took a while), and as far as I know she was never asked about her GPA or transcript. I think I was only asked for transcript for government jobs that had requirements like 3 years of math or some statistics for some data analytics positions.

Nevertheless, most masters do want as a minimum 3.0 GPA. But there are masters programs that do not have specific GPA(especially online programs), and some may take students with lower GPA with significant job experience on condition of getting at least 3.0 first semester. Basically often masters program have often requirement for graduation to have at least 3.0. That is why they may not want to take students with lower GPA.