Just finished a few simple arrangements for flute/cello/piano. All cloned from the same template.
These are around 3-4 minutes each. Exported audio as mp3. File sizes around 5-6MB and took seconds to export.
On the last song, which is less than 3 minutes, same instrumentation, etc. Audio export took almost 30 minutes for mp3 and created a 330MB(!) file. Tried to do wav. file export. Took about 20 minutes and created a 1.82GB file. Both exported audio files play normally and have the correct length.