Try turning you computer off then ie resart it

If you are really wanting to rescue these shots try Topaz Sharpen AI possibly in conjunction with Topaz De-Noise AI. I have had some amazing results with these two apps. Topaz Sharpen AI has rescued images that I normally would have binned

Still interested to know if during import you click on "copy" or "add" the reason I ask is you would save yourself a lot of time if you import your images directly into Lr and then use the reject flag as you go through them and then delete all your rejected images at once when you have been through them. This is my work flow and sometimes when there is a large number of images to edit I am still rejecting/deleting images on the second or third time I go through them.

Yes Yes Yes so many reasons, it runs faster the auto develop buttons works so much better the texture slider, the de-haze slider, the profiles panel.
2 years ago I was seriously considering going to Capture One but Adobe fixed the problems which was causing Lr to slow down so I am staying with the Classic CC version and I don't think I would have saved any money by changing and pay in Australian dollars so its more especially when you consider that I live in New Zealand and they start out as NZ dollars

I treated myself to a Small Rig L plate for my new a6600 and a new flash as my old Nissin is starting to play up, so I ordered a Sony HVL-F60RM flash. But hey I can't plug my Godox PB960 external battery into it when it is on the hotshoe and it it looked like it was going to be too difficult to sort running it on a bracket without spending a huge amount of money, so it went back and I ordered a Godox Wistro AD360, it's pretty big so I have a bracket ordered and I have ordered a Meike Multi-Interface Sync cord as well from Aliexpress, which if I had been able to find that sooner I would have kept the Sony flash. However I'm happy getting the Godox as it will take me back to the days of using a Multiblitz Press Universal flash. A round head no zoom and lots of light, although far more power settings than just half and full.
If I include the new a6600 and the 100-400 zoom Christmas has been rather drawn out lol

Have you got select the "Current/Previous Import" collection during import box checked in general tab in preferences.
I'm not sure if you are loading the images into your computer before importing them to Lr or if you import into your computer via Lr.
My reccomendation is to use Lr to import images into your computer to put them into their final destination folder otherwise it is just double handling.
You always have to select the source when importing

Why do you save the tiff in Lr, that would only clutter things up, tiffs etc are for export, if have finished editing export for printing etc there is absolutely no need to keep the export in the Lr roon catalogue

Bulb was the setting in which the shutter had to held open physically i.e. press the shutter button for a predetermined length of time and when you release it the shutter closes
The "T" setting is much more convenient this is where you press the shutter button and release it and the shutter stays open until you press the shutter button again.

The logical thing is to remove the mirrors from DSLR cameras and replace the OVF with an EVF. A mirrorless DSLR type camera would have so much room in it to fit a truly hi res EVF in it plus all the other hi tec stuff and have room for a high capacity battery, plus with all the Canon and Nikon lenses available for their DSLR cameras it just makes sense. As far as I'm concerned the logical thing for Sony to do with it's A-mount cameras is to remove the mirrors altogether as they have the sensor tech already and the AF tech to be able to do it

The MM means manual mode and the flashing -2.0 means that you are more than 2 stops underexposed keep turning either of the exposure adjustment dials until you get your exposure correct, if that doesn't work remove the lens cap or change your ISO

I have a sd card slot in my PC but I use a USB3 card reader because it is much faster.

I tried both Zerene and Helicon Focus, and chose Helicon focus because it will work with raw files and will output a .dng file. That being said I also Ps to stack as well.

It sounds like you need to organise your drives so that they always keep the same drive letter and you do that by starting them off at M:
you just need to rename them in Disk Management and then if you have written XMP files it might be easier to create a new catalogue in lightroom.

I find that for situations where a catalogue catastrophe occurs and you run the risk of loosing your edits, then making sure the "Automatically write changes to XMP" check box is ticked in the metadata tab of the catalogue settings dialogue box in Lr, will guard against this possibility. Computers and hard drives are fallible so using every avenue possible to back up your images and edits is the best way. For instance if you have to revert to an earlier backup of your catalogue which will not have the edits of your latest imports then having the XMP files with your images means that Lr will automatically write the edits into the newly reconstituted catalogue and I can tell you from experience just how gratifying that is. Remember 3 copies of your images is recommended one on your main hard drive you use for storing and working with your images, one on a back-up hard drive, and one in the cloud. For cloud back-up I use Backblaze which is the cheapest and the best @ $5 for unlimited back-up storage.

Yes I think lightroom has improved considerably to the extent that I have given up the idea of changing to another program