Yes, RS has become unstable with there products, probably employing sales reps as buyers than using higher salary electrical engineers.
I ordered from a RS depot in the south of England and then would collect when i was passing on my travels especially large steel enclosures. I ordered some large, and new to RS range Ferrite Chokes as the price was not bad. However when i called to collect the ferrite cores were half only, DERRR!? ie they show the 2 sides in the Pic but you only get half, and one was broken as they were loose in a posted jiffy bag. In the end i never got all my money back from that order. Nope RS are expensive and expensive on P+P even if the order is hundreds. I also find there actual counter staff condescending even on a pick up drop.
So I advice all OzInverter makers to order from Farnell in the first instance as they now have many depots scattered across the World. Although i did have once some Fake Driver chips, not in spec, but that was soon rectified. Capacitors especially the big ones we use, i state spec a make and then actual physical can size.
Regards the large Ferrite Cores, i give details of the actual manufacture in Bulgaria who will send just one, (a Pair of half's) anywhere in the World and they are always well packed.
Fleebay and AliEx-press are now pot luck what you will get. At first 2015 i got what ordered and tested each large FET and chips. Now 2020 its real bad.
Scruff, the World is ever changing. And today i have to test every component i purchase.
A pic of the special 8010 PWM chip for toroid's, with all the correct codes in 2015 could only be purchased from Ali-press, had to buy 50, but heck they were not expensive in the bigger picture of things. Some later 8010 chips were missing some code on their chips and they wouldn't do some of the tasks ask for and in the spec.