There is waste water scale on internal surfaces: RO filter and pump. You will need to go through the Descaling process.
The reason that filtering time is increasing is due to waste water scale deposited on filters and internal surfaces.
To minimize the effect of waste water scale deposits, it is important that you always empty out the remaining waste water in the tap tank before refilling. The water left in the tap tank contains highly concentrated contaminants filtered out of your tap water. The level of the contaminants in the left-over water can be up to 6 times higher than the water coming out of the kitchen faucet. If this water is not discarded, the unit will develop scaling much faster and will require more frequent descaling. If you are in an area with hard water, you may need to descale more frequently.
If this does not help, please contact Customer Support, and they will replace the base, if under warranty. If out of warranty, they will give a courtesy base replacement.