[BUG] DIspose() won't dispose sometimes. Throws exception

[arunprakashn]

Version
5.0.21

Describe the bug
Does not DIspose properly sometimes.

Code to Reproduce
Unable to provide. This is a high throughput read/write but protected with "lock" statements

Expected behavior
Should Dispose properly

System.Exception: LiteDB ENSURE: discarded page must be writable
at LiteDB.Constants.ENSURE(Boolean conditional, String message)
at LiteDB.Engine.MemoryCache.DiscardPage(PageBuffer page)
at LiteDB.Engine.DiskService.DiscardDirtyPages(IEnumerable`1 pages)
at LiteDB.Engine.TransactionService.Dispose(Boolean dispose)
at LiteDB.Engine.TransactionMonitor.Dispose()
at LiteDB.Engine.LiteEngine.Dispose(Boolean disposing)
at LiteDB.Engine.LiteEngine.Dispose()
at LiteDB.LiteDatabase.Dispose(Boolean disposing)
at LiteDB.LiteDatabase.Dispose()