We keep fighting about the same issue. How can we break the cycle?

Work out whether the issue can be solved or needs to be managed; many differences in marriage never disappear, but can be arranged so they no longer spark quarrels.
Allah praises those who restrain anger and forgive (Al ʿImran 3:134), and the Prophet ﷺ guaranteed a house in Paradise for one who gives up arguing even when right (Sunan Abu Dawud 4800). Practical steps: choose a calm moment, not right after the issue arises; each explains what they really feel and need behind the issue; find a specific compromise and try it for a month; agree a signal to stop when voices rise; and write the agreement down. If every quarrel ends with dredging up the past, a counsellor can help break the pattern. See Emotional communication.