Ping time up after 2-3 days

Hi…

Anyone have problem with ping time go up after 2-3 days mikrotik router running ? I use v2.8.28 and 3Com gigabit ethernet with RB44. Right now I already move to 2.9.20 with routing test… but I wonder if this is also happen with v2.9.20

Any comments and suggestion welcome…

Thank you for your attention & help.