diagnostic error code -4403D on Macbook Air

My son's MacBook Air (mid-2014) sustained water damage and corrosion to logic board.

I used following link to be able to remove and clean logic board:

https://www.ifixit.com/Guide/MacBook+Air+13-Inch+Early+2014+Logic+Board+Replacem ent/24746

A quick cleaning with isopropanol and it worked again!

However I decided to run the Apple Diagnostics by starting the laptop and holding "D" as suggested in Apple Diagnostic Testing instructions.

The screen appeared, "Internet Recovery" - This may take a while... and a few moments later an error message appeared "-4403D, offering a web page

Apple.com/support to check for answers. However I can't find out what this means.

The laptop appears to be working correctly except when going into power save mode and turning off computer. Once that happens, I have to restart the laptop.

If I put screen into power save mode, no issues coming out from that.

If I close laptop and open again it appears to come out of power save mode.

So really minor issue but I wanted to run diagnostics to see if it will return some error code to understand which part may be malfunctioning.

Any suggestions?