It has nothing to do with your pc - it is a knowen bug from dlc release which EA doesnt seemse to care
- make sure to disable any programs that influence your GPU - like msi afterburner or any other overclocking
- then RUN through the mission until the lift and con with liara
- make sure to save after every cutscene - just in case
- make sure just in case to spam the command screen (shift) and/or ESC after every conversation
- after that DO NOT watch the memory with the opening sequence first (forward after the first battle)
- DO watch the signal memory first (right after the first battle) then go back and watch the other one
In the case of this problem happening again after any cutscene (for me in the cerberus HQ) then do the steps with turning off GPU programms and the spamming thing again 😉