Repeating command blocks not repeating correctly

The map I am making requires quite a few repeating command blocks. The repeating command blocks were doing their job only to suddenly slow way down. Many of them are still working at the correct speed, but a few commands, like /give and /effect, repeat every few minutes instead of every tick. Most of the teleportation commands are repeating correctly, but some still aren’t. I have tried disabling and enabling command blocks. I have gotten rid of my ticking areas and replaced them. I have exited the world and restarted. I have restarted my Xbox. None of these things have had any effect. I should also mention that the game is freezing up every 5-15 seconds. Disabling command blocks had no effect on this freezing. It happens whether command blocks are enabled or not. The freezing started around the same time that I noticed many of the repeating command blocks were not repeating at the correct rate. Some of the repeating command blocks have modified tick delays but nothing more than a couple seconds (40 ticks), so I have no idea why these commands are taking so long to repeat.