Here's a fantastic site/resource for that kind of thing and especially for identifying cells/specs when you dig into battery packs. This is the page for the green 25R (there was also a light blue one apparently) and it has a .pdf link to the Samsung official whitepaper. Says it should be around 22 milliohms in the 1-10 amp zone. That's when new, and it could range more or less. With cycling and aging/heat resistance usually goes up slightly or moderately after awhile...the cells may still deal with high current just fine but will reduce in capacity and throw off more heat when you put the beans to 'em.
https://secondlifestorage.com/index.php?threads/samsung-inr18650-25r-cell-specifications.1738/ (they have a main database page where you can scroll through alllllllll the cells or filter by various parameters to narrow down a search. It's great.)
All that said, the resistance rating is given for tests done with specialized and very accurate lab equipment under certain test conditions. Our battery chargers are nowhere near this level. Some chargers are better than others, some will change the value shown every time or when the same cell is put into a different slot, and some are so far off as to make the feature worthless. Best you can do is keep all of the contacts clean (charger and cell both) and ensure there is good firm contact with the cell once inserted. Sometimes on my chargers the resistance will read high (like stupid high even on new good cells) and then come down to a normal level after a bit of charging time...but often when I see that happen I can pull it, reinsert it and give it a twirl, and it reads normally (and often lower...to where it should). Disadvantage there is smarter charges will see that high resistance reading and just provide a very low charge rate (safety...so as not to overheat) and then increase the rate if it sees the resistance drop later. If you know the cell is in good shape you can override that smartness and just give it a manual charge rate. To read your cells' resistance accurately you need to buy a specialized tester or a bench supply and hook things up correctly. But as long as you can see that it's still low-ish and within or close to its range, all is good. Even though your cells sound like they're pretty close to new, don't be surprised if your charger says things like 50 or 80 or 150 for resistance...just how most chargers are.