Raspberry PI 3B+ File Copy Fails, Works on 3B

Has anyone else seen wired network errors with the 3B+ during file copy?
I have two PI's, one is a 3B, the other the 3B+.

I have installed OMV on the 3B using the image in OMV_3_0_99_RaspberryPi_2_3_4.9.80.img.xz and have had no trouble settings up SMB shares that I can copy to and from multiple Win10 machines with no issues.

When I try and repeat the process on the 3B+, using the same image, everything seems to work the same, but when I try and copy off the 3B+ to Win10, the copy process fails after about 30 to 90 seconds. I am using the same drives, power supply (3amp), SD card and network cable. I reinstall the image each time I swap the SD between the two boards, using Etcher to write the image.

I have set up the 3B three times from scratch, and have never had a problem. I have set up the 3B+ four times and its file copy has never been reliable.

The web interface on both appears to work identically with both boards and I have no observed network issues that affect the web interface.

I am new to OMV, so have I missed some post somewhere that I need to follow for the 3B+ ?

Thanks for the pointer to the post about EEE. Being a newbie in the Linux arena, I eventually worked out that what I needed to do was edit the config.txt file in the /boot directory and add the command dtparam=eee=off at the end of the file. I eventually learnt enough to do that, confirmed that the config file had actually been edited and rebooted the 3B+. No change. The 3B with the same SD card swapped into it copies 100% reliably. The 3B+ fails every time. Same files, same everything, other than the case and the PI board.

As an aside. I also have a SD card with LibreElect and KODI which I use only as a media player to play video files on my LAN. When I use the 3B+ as the media player it appears to work fine. So my fallback is to use each PI where it works and accept that the 3B+ and OMV and me are not destined to be. I would like to beat this issue if possible so any other advice would be acted upon.

Post I followed was: New approach for Raspberry Pi OMV images post 170