E7440 does not boot with docking station

My thanks in advance for your reading this post, and any insight that you might offer.

I recently purchased a used E7440 off ebay, in working condition, but sold "as-is".

It is in good shape.  Some basic specs: 1920 x 1080 touch screen, 2 x 8gb DDR3L RAM, 512gb mSATA SSD, Win10 Pro current updates, legacy BIOS boot.

Everything seems to work fine, although I've only been using it occasionally for two weeks.

Then, I tried to dock it to an E-Port I.  I've been docking an old E6420 to this E-Port I for over two years.  Upon docking the E7440, nothing shows on screen.  Power LED on the port went on, then off, then on, then off, etc.  Not a regular pattern to call it "blinking."    Finally, I undocked the E7440, to find it not powering up normally.  I did a hard power-down, then powered it back up to see it go through corrupt boot recovery.  After a couple more reboots, it did recover to normal.

Same thing with an E-Port II, and finally with an E-Port Plus II with 130W power supply.

Please help.