I am aware that I am sometimes unable to open the version history excluding a modern one within Office client. The investigation of a Support desk showed that the event was caused by a network that i was using. However, the Support's information has not been persuasive for me because I can open a new version history and Office files within One Drive for Business and I have no problem with the performance at all. This could confuse me in case I need to undo the files because I have no idea of the timing I should do so. Consequently, I hope you will be able to improve along with the server adjustment the behavior that the possibility of opening old version history is different from environment to environment and that I am occasionally unable to open it.