mobile data – Hotspot stops uploading to internet suddenly

I have Android 2.3.6 (rooted) on my Samsung I9003 Galaxy SL .I use the “USB tethering” option to connect my laptop to the cellphone and sometimes “Mobile AP” as a hotspot.

When I try to upload anything usually bigger than 1 or 2 MB to internet, all of a sudden, the internet connection drops. I didn’t have this problem a month ago.

After the connection drops, I can’t receive or upload anything and can’t even visit a website… I can’t even get a ping result. On the phone, the mobile data icon is still there, but no signs of sending or receiving.

Then I have to uncheck phone data (Use packet data) under “Mobile Networks” for a few seconds and again recheck it, to reset the entire connection; and then everything works again.

I figured out if I keep refreshing a web page (somehow downloading anything during any upload) the connection won’t drop. Or when I use google Duo in chrome browser (downloading and uploading at the same time) the connection won’t drop, but when solely uploading anything… the connection to drops.

Any solution is appreciated.