Signal history export size question



I'd like to monitor VHF beacons for 24 hours or so to estimate the propagation variability (morning & evening). The "Signal History" feature seems appropriate for that.
However, 1 hour of data makes 72000 entries in the export file. 24 hours would then make 1728000 entries that I can split into several Excel files.
Yesterday evening, I launched the signal history recording. This morning, when exporting the csv file, I only get around 50 min of recording (the last 50 min) and a file with some 60000 entries or so. I hence don't get the few hours of recording exported.
My question : is there a file size limitation of the export csv file ?

Thanks in advance for your help.

Gaƫtan, ON4KHG