I never use double-sided tape...in fact, I remove the adhesive that some else put on them.
Because reelstrips are normally stored rolled up, they should naturally "snap" into place into the edges of the reel basket slots and hold in position with the notches.
BTW You can feel the raised notches on the outside of the reelbasket rims, where the basket spokes are closest together.
Measure your reel strips.
They should be 3-5/16" wide by 27-7/8" long.
If narrower, they may be S2000 reelstrips, rather than S+ reelstrips.
Or they were S+ reelstrips cut to fit narrower S2000 reel baskets, now are too narrow and no longer fit S+ reel baskets.
What are the numbers of these strips on the bottom?
Also, check inside the slots inside the edges of the reel baskets for debris with the tip of a small flat screwdriver.
The reelstrip edges should be allowed to fully fit inside the edges without any effort.