Looking at Giant Canada site looks like your Reign is spec'd the same hub as my '19 e-Trance.
I went through 3 hubs before they finally replaced it with a DT350 and believe this is Giant's go to solution as I've seen others here getting the same replacement.
I was forced to get a backup...
If you cut the line maybe it wasn't a clean cut?
Flip the bike upside down and see if that makes the lever feel change and if so that would be air in the line moving. I've found gravity bleeds work best with my Shimano's especially the rear due to length and bends. Good luck!
My method has been drive side out, lube the lower part of chain, grab the top part of chain and slide it right to left til you have the next lower section to lube. Repeat 3 or 4 times and your chain is lubed....
Note, cranks will spin so the non-drive side has to be clear
I get some chain slap there but paint chips away and is just in the top. That looks different, like constant dragging or something...
I previously went through a frame warranty {crack in seat/top tube joint) and put rubber mastic tape on the previous frame and have been meaning to get more to...
I started having power cutting out issues on a ride. Finally noticed one of the 2 little screws holding the female battery receiver was missing and had play. Luckily found a replacement in my toolbox, snugged it up and all good since...
It's the same basic procedure. Loosen up the security torx bolts slide/adjust as appropriate. First try with the battery in, loosen the two bolts and "jiggle" it to let it settle into place then re-tighten.
If that doesn't work and with the security torx bolts loose does the battery drop as...
With the battery out there are 3 hex bolts for the lock. Loosen those 3 and you can slide it to where you want it. I imagine you'll want to slide it up just a smidge to bring the battery tighter to the frame.
Those 2 security bolts in the picture will adjust the distance of lock to latch which...
Unfortunately went through a frame warranty with a crack at seat/top tube weld. Vancouver Giant handled and treated me well and was only out for a couple weeks... Unfortunately not the same colour but here's the replacement...
I had previously gone through a controller wiring issue where the plastic connector had busted at the motor location. Replaced and all good.
Started getting the odd random power down and reseating the battery seemed to fix it at least temporarily while on the trail.
Went to clean the contacts...
I got my bike in Dec and initially had it setup charging on the bike in the garage. Couple weeks in noticed the battery health dropped to 96% so started charging off the bike and inside the house. Since then has remained stable at 96% but I notched that up more to the charging temperature but...
Mine did this out of the blue so took a Q-tip to the battery prongs on the bike after checking all the usual and after a few dirty Q-tips finally came clean and no issues since. Found it best to pull the Q-tip between each prong for the cleaning...