Hacky way to keep micro USB firmly in place?

I've solved a similar issue using Sugru and lego men :) they had a nice guide here

https://sugru.com/tech-gadget/how-to-organise-your-cables-with-lego-minifigures

You could also just use the glue to make something that is custom moulded round the wire and acts like a brace to your laptop, preventing it from wiggling as much.

I would try anchoring the cord to the keyboard, leaving a couple inches of slack between the anchor point and the micro USB plug.

Any pulling on the cord will stop at this point, instead of continuing to the plug and disconnecting it from the jack. Also, the cord can still be unplugged (allowing something else to be plugged into the port) while remaining anchored.

Possible methods of anchoring the cord with a bit of slack at the micro USB end could be:

1) A Strip of strong tape, holding a couple of inches of the cord's length to the back panel.

2) Glue, used in a similar fashion as the tape, would also work. A glue that is flexible after drying (much like the tape is flexible) will "give" a little and still hold. A hard, brittle adhesive might crack and release the cord.

Having a good length of the cord held by either of the materials will hold better than anchoring at a single point, since the stress will be transferred from the cord (and absorbed by) a greater amount of surface area of the materials being held, and to the glue/tape itself.

-If the tape is wide enough to come over top and bottom of the keyboard it will help even more with holding the cord.

-Glue should be applied thick enough to completely surround and embed the cord, since it is holding onto both the cord and the keyboard's case, while absorbing any stress on the cord.

I Have used "Gorilla" brand tape or silicone-based glues for this type of cord anchor several times, and it has worked great for years on most occasions.

Another option is a mechanical anchor of some sort, such as a wire clamp, or zip-type cable tie screwed-in to the keyboard.

The tape solution is more temporary than the others; but I can't really see why the cord isn't permanently affixed in the first place, unless a different length was sometimes needed.

If it were my keyboard, I would use a permanent anchor.

I've used micro USB right-angle extensions to keep the connection secure. It works because a light amount of tension on the USB cord ends up rotating the male end of the plug ever so slightly inside the female end, rather than trying to disconnect. If you pick a sensible direction of 90 degree bend, it may be beneficial.

The drawbacks to this hack are that you have to spend some money to see if it works, and if it does work it can result in breaking the port if you tug at it too hard.

If you bend a paperclip properly, so that it is just two wires running parallel with a 180* curve in one end, you could make a latch mechanism of sorts that hooks under the keyboard (the closed end with the bend) and the cable goes in from above. The open end then hooks on the cable side of the connector, pulling it towards the keyboard.

Hard to explain and not sure if there's anything to hook onto under the keyboard.

The picture doesn't show the port. You don't describe where on KB the port is, so I can't be very specific. An ideal joint will retain its ability to flex rather than break or disconnect. I don't know how you'd do that with the micro USB cord - some way to maintain a gentle pressure directly towards the port... Anyway, my only concrete suggestion is to glue or tape a 'splint' under the port and then tape (or otherwise fasten - would rubber bands work??) the cord to the splint - similar to how a finger splint immobilizes a finger. As long as the splint is rigidly attached, it should help keep the cord plugged in. Perhaps you should consider a wireless KB...