Porting to Tunetalk soon since it’s cheaper and has more data than my current CelcomDigi postpaid. Will Tunetalk network ride on the CelcomDigi integrated network where NIM is already completed?

Anyone got randomly disconnected from their 4G data before while driving to other states? Noticed that whenever I travel along ELITE/PLUS highway my data will be disconnected for a few seconds then reconnect back. I wonder if it’s because I travel through an area where the network integration isn’t completed yet.