Why did repeated "R" values occur in Bitcoin transactions before? Please explain why earlier the repeated values of "R" occurred in Bitcoin transactions.

For example, this transaction has a repetition of the value "R":
https://www.blockchain.com/btc/tx/19d66411a5aa716a04b37197c11c93c9446a54694a2d2302093d8b0a93ed5d83

If you look at RawTX:
https://btc.com/19d66411a5aa716a04b37197c11c93c9446a54694a2d2302093d8b0a93ed5d83.rawhex

repeat value "R":

R = cabc3692f1f7ba75a8572dc5d270b35bcc00650534f6e5ecd6338e55355454d5

What was the reason for this? Explain the reason for this error?
The R value is the result of EC point multiplication between the k value (known as the nonce) and the secp256k1 curve's generator point. It is effectively the public key for k. The only way that an R value can repeat is if k is also the same. Given that k is a 256 bit number and is supposed to be chosen completely randomly, k should not repeat unless the random number generator is broken.

Considering that k is generated at signing time and should be random, we can conclude that whoever chose k for those transactions has a faulty random number generator which is either outputting a fixed value or a small value which increases the probability of k being repeated. There is no good reason for this to happen, so this error comes from either a faulty RNG or a completely misunderstanding of how ECDSA works.