i am 100% sure it is R03 firmware issue. if i use any R01 branch firmware then no issue never single disconnect, never speed down always work fine.. And i already using R01 firmware continue 24x7 since 6 month never ever issue.
But, when i use any R03 firmware then start problem unstable internet, slow speed, high ping, internet hanging issue..
i use 5G SA.
Other user also face same problem with R03 firmware and no issue if they start use R01.. Already discuss on this forum.
Read forum post.. 3 users already having same problem.
I hope this is enough to you and quectel for accept this R03 firmware issue..