HARIO Replacement Metal Filter for Coffee Syphons

I bought the Hario Next which came with the stainless filter and it’s been great. So great that When my brother got the TCA syphon as a gift, I knew he would find it a hassle to keep and maintain the cloth filter that came with it, or having to get the paper filter type and having to reorder more regularly. So I bought this for him. The other reviewer here has stated that s/he noticed some grinds had fallen through and was unsure if it’s because it’s not compatible with the Original TCA-# line of siphons. As far as I know Hario has stated that they are compatible. I also sometimes notice grinds come through but sometimes not so I think it may have something to do with ensuring centre placement and a good deal, rather than say grind size or anything like that (I usually use between a drip and espresso setting). I grind with the Breville Dose Control Pro burr grinder and the Smart Coffee Guide website has a chart of recommended grind settings for different coffee making methods. For syphon it is 16-44.

Another filter by Diguo seems to be quite popular but this one is by Hario themselves and retails for cheaper.

I was excited to try out new stainless filter as it seems easy to clean (which it is), but for some reason it doesn't filter correctly. When brewing, some coffee falls down into the neck of the syphon. It says it fits all Hario syphons (Mine is tca-3) so I'm just confused, is it a defect?