Messages from `getMessagesByTimestamp` not responds to channel `messageOffsetTimestamp`

I’m trying to fetch group channel messages via getMessagesByTimestamp and local caching API. Seem local caching API responds to channel messageOffsetTimestamp, but getMessagesByTimestamp does not.

Should i filter those outdated messages manually or this is a bug issue ?

// Get messages via MessageCollection
channel.createMessageCollection({
   startingPoint: startingPoint,
   limit: 100,
})
.initialize(MessageCollectionInitPolicy.CACHE_AND_REPLACE_BY_API)
.onCacheResult(() => {})
.onApiResult((error, messages) => {
   // All messages createAt >= channel.messageOffsetTimestamp
});


// Get messages via Group Channel getMessagesByTimestamp
const params = new MessageListParams({
   prevResultSize: PAGE_SIZE,
   nextResultSize: 0,
   reverse: true,
   isInclusive: true,
});

const messages = await channel.getMessagesByTimestamp(
   startAt,
   params,
); // Messages with createdAt < channel.messageOffsetTimestamp not filter out

SDK version: v4.0.0-beta.8