Multiple connection drops, T2 & T3 time out errors, low upstream power level

[Nstableinternet]

Please! I've had this constant connection drops for about two weeks. It happens several times a day and very randomly. I've tried different ways and it can't solve the problem. Please, someone please help!

What happens is:

• the connection drops at a random time throughout the day
• the lights on the modem are all on and not flashing
• the connection light on the router will turn orange meaning it's off
• on the xfinity app it says the modem is not connected
• after several minutes, the connection will be back on by itself
• Every time it happens, there's a T2 or T3 time out error on my modem event log page. I'm not sure what it means.

What I have done:

• The same issue happened two months ago. I called and one agent said that my modem was not synchronized with their server and fixed that. It helped for one day and it started happening again. Then they sent a technician to check the outside and that helped for two months.
• After it started happening again recently, I called Xfinity a couple of times again. They sent a technician to check the outside again and said it was all clear but it didn't help.

This could be what the problem is but not sure how to solve it:

• I called my modem manufacturer last week and the technician there said my upstream power level was lower than the recommended range. He said it should be between 45 and 50 dBmV. My four upstream channels were at 43 or 44 dBmV.  He told me it might be caused by the updates from xfinity and it was something xfinity could adjust on their end. I should not have connection drops once xfinity raises my upstream power level up to the recommended range. 
• Howevever, I called xfinity to fix this upstream power level problem and the agents on the phone did not seem to understand what this was. 

Could anyone please let me know if the upstream power level is something xfinity could adjust? Is this the actual problem? 

Hope someone could help me! Please and thank you!

[CCAndrew]

What’s your downstream signals and SNR? Modem (and other equipment) levels aren’t set remotely. They are based on what comes out of the tap and factoring in distance and splitter loss. Your 43-44 is well within spec

[Nstableinternet]

Thank you for answering!

My downstream power level is between 8 and 13 right now and SNR is between 34 and 37. 

I have had 5 connection drops this morning and now my upstream power level is down to 42 to 43.

My modem is an Arris Surfboard SB5183.

So if I understand it correctly, you mean my upstream power level seems fine and it cannot be adjusted remotely. Will be it able to be set by a technician outside my building?

Or, could you please let me know what you think the problem of this constant connection loss is? Thank you!