I think the CHF strength comeback more has to do with better than expected swiss economic data, that came out yesterday. This means less need for SNB to lower rates next session and market is pricing that in (it had priced in another two rate cuts for this year after the sudden rate cut of SNB).
CHF also gained strength back against EUR yesterday. Although EUR got some of it back, due to slight uptick in eu inflation → less probability for ECB to cut rates next week (but still quite high probability).