Audio/video playback lags making animatic

First off im using pro 1.5.
I’m trying to make an animatic. I trim panels according to audio then play clip to check and playback can’t keep up. It will skip panels and the edits I did don’t seem to match up to audio.
I hope this is explained well enough for an answer.

This depends on your system’s RAM and video card RAM.
Remember that this method is not intended to let you play through
the entire board. Select a subsection of the project, let it play
once in memory (looped) and subsequent playthroughs should
be at speed or close to…

If you need to see the entire animatic then do a render to movie
(half or quarter resolution if memory and/or time are an issue).