USB-C Port doesn't work properly. Doesn't charge correctly. Any ideas?

Resolving USB-C Port Charging & Headphone Connection Problems for Pixel 3 XL

Symptoms:

1) Headphone connection became spotty. Music would frequently stop playing. Flipping male USB-C connector helped for a while before it completely stopped working.

2) Fast Charging through a travel adaptor stopped working, even when using Google’s Charger. However, slow charging through USB-A to USB-C cable from the same travel adaptor worked OK.

3) Fast Charging through normal outlets (in Germany) using Google’s Charger failed when USB-C connector was inserted one way but not the other even when using multiple cables.

4) Often had System Notification with greyed-out USB connection choices.

Steps Taken to Resolve:

1) Initially considered that problem might be software related. However, were that the case, Google would have long since fixed or there would be many more occurances of it. Forums suggested that the issue was occuring randomly through time. If it was a software problem it would be unlikely that it would only sometimes work.

2) Determined problem was not due to Google’s Charger or USB cables.

3) USB-C specification was tested for 10,000 connections, so unlikely that it would fail under normal circumstances (unless of course Google’s implementation was somehow faulty).

4) I noted that some people successfully resolved their charging issues via cleaning.

5) Removing lint from around the outside of the female port’s central pillar using a paper clip prong slightly increased the probability that it would Fast Charge. Headphones started to very rarely connect (<5% of the time).

6) Compressed Air Can didn’t lead to noticible improvement.

7) Electrical Contact Cleaner Spray would likely be helpful, but have heard that it can leak under smartphone displays and ruin them, so was a bit wary to do any more than dab some around. That didn’t help, but I assume that it might in larger quantities (as that is precisely what it is for).

8) Inspired by @Jason LeMonier’s post above, I then used a metal Needle Threader (see Wikipedia for a picture of one) to gently wipe/rub the electrical contacts on the side’s of the female port’s central pillar for maybe 10 seconds on each side.

Outcome:

After this final super-gentle wiping/rubbing:

1) Headphone adaptor started working both ways again (went 10 for 10 attempts).

2) All charging cables started Fast Charging both ways again.

Additional Thoughts:

1) Problem was likely dust or small amount of corrosion on one or a few of the electrical contacts (see USB-C Specification for details).

2) Due to the fact that higher voltages can jump wider air (or dirt) gaps, in terms of sensitivity one will likely see the following behavior:

a) the headphone adaptor will stop working reliably >> lowest voltage connection

b) Fast Charging requires specific pin connections to be made (so if these pins are dirty or defective the phone will stop fast charging from one or both ways).

c) Slow Charging is generally the last to fail (even though voltage is lower than fast charging) because it relies less on specific pin connections.

Hope this helps!