usually nangyayari yan pag may line issue, congestion sa area, or may problema sa modem/lan cable kahit sa speedtest umaabot muna tapos biglang drop girl. try mo muna direct lan connection sa pc para sure hindi wifi bottleneck, restart modem pero wag madalas, tapos check kung updated firmware. pero real talk mare, pag paulit ulit na ganyan kahit ilang tawag, kulitin mo talaga cs at magpa line check or modem replacement kasi hindi normal yan. document mo yung speed tests para may resibo ka