The problem with training speed

Previously, the speed was 5-6 seconds/it (program version v24.2.0 with a branch -b sd3-flux.1. I have now installed v25.2.1, as I understand it, flux is already integrated, but now the speed is 50-60 sec/it. I did not change the json file with the settings. Can you tell me what the problem is, or help me download version v24.2.0 with branch -b sd3-flux.1.