Not sure I'd call 2.8 ohm LR. Standard should be 2.3-2.5 and LR under 2.0 in the 1.7 ohm range. What voltage are you using?? What pg/vg ratio are you using?
Only other thing to consider is if they worked GREAT at first and only lost vapor after cleaning and tweaking with paperclip is that these are disposable and not exactly known for being as good the second or third time around.
Also were they DRY when you reloaded and vaped. Water is not really vapable and may have to be boiled off before you'll have full vapor production from liquid.
If you've never had good vapor consider higher or 100% VG. If they crashed after cleaning consider keeping them fairly moist to extend life and when they croak maybe clean and store as backups. Only other thing to consider is letting them soak overnight after refilling. This lets the
juice get in all the nooks and crannies and if you hear bubbling consider blowing out excess juice. Nothing kills the vapor quicker than a blob of juice gurgling in the bottom. Remember there is a sweet spot somewhere between too wet and too dry where the production should be best.