S&T Internship after Debt Advisory

I am a first-year university student from Europe and I have an offer for a Big 4 deal advisory/debt internship this year. It was described as where m&a/dcm come together. While it does sound interesting and there is rarely any better first internship for your resume, I wonder whether it would be a good idea to do it since I am quite interested in S&T too. Planning to apply for S&T (preferrably fixed income) internships for 2021, would this internship even help in the process or would you rather see it as a deal-braker and advise me to rather apply for e.g. research internships for Summer 2020 as a "pre-internship"?

Please note that I am from Europe and will also take part in a London trading spring week programme this spring. Also, the debt advisory internship would make me miss most of the third semester's lectures, most likely making my grades worse.

Any input or additional questions about my background are highly appreciated. Thank you very much.