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Before Dec 2019, UMobile throttled the download speed to 0.5Mbps if the GX30/50 subscriber had exceeded 100GB of data for the month. Starting in Dec 2019, UMobile seemed to have relaxed the FUP = no throttling - likely because of market competition from TM Unifi Mobile true-data-unlimited RM59 promo that was launched in Nov 2019. Maybe since Jan 2019, UMobile only throttles those top 5% data-abusers who use more than 150GB per month. Did you.?

Another reason could be network congestion in densely populated areas from 8pm to 1am. If so, if you are connected to the Internet in the afternoon, keep your mobile device connected until night-time or sleep-time because network connection has a set capacity of 60 users per cell tower at any one time and is on a 1st-come-1st-serve basis.
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