Repost of MC-1541 for bedrock.
When a stronger effect overwrites a weaker effect the weaker effect is gone forever even if the weaker effect had a higher duration than the stronger effect. This was fixed in java edition in 1.15.2, by making the weaker effect come back after the stronger effect expires, but hasn’t been fixed on bedrock edtition yet.

How to reproduce:
1. Run this command: effect @s regeneration 99999999 0 true
2. Run this command: effect @s regeneration 2 1 true or throw a splash potion of regeneration 2 at you.

What I observed: After the stronger effect expires the weaker effect doesn’t come back, it is completely deleted.
What I expected: After the stronger effect runs out the weaker effect will come back (If the weaker effect is longer than the stronger effect).

In survival this can often happen when a beacon overwrites the effect. This can cause you to lose 8 minutes of an effect if you enter a beacon area. Or if you use a totem of undying, the fire resistance 2 effect (See MCPE-52364) was able to cause you to lose the fire resistance effects from a potion.
When this got fixed on java edition there also were some bugs that related to it MC-169930 MC-169839 MC-169840 MC-169965. MC-169964 is also currently a bug in java edition. Hopefully they are not in the game when it gets fixed on bedrock edition.