Only 13 % of context is used but model starts to forget things and repeat everything?

I use llama serve and webui of llama server. I have had long discussion with my chatbot and then randomly it just starts to forget almost everything. It starts asking same question, I correct it and it apologizes, but then next time it asks the same question with almost same words (or maybe even fully same words).

What could cause that? Something on my CLI parameters? Wrong cache settings?