Hello. Sieron here.
I found this weird bug with SCP-106.
So let me take it from the top.
I was out trying to find this mask (SCP-1499) that transport you to another dimension. After a while of search, I found it. But as soon as I grabbed SCP-1499, I hear SCP-106 make his appearance. I quickly ran out of the room where SCP-1499 was lying dormant, and closed the keycard door, while SCP-106 was appearing in the room. And so, I ran away.
I thought it was still following me at that point, but after a while, I noticed that it was not following me, and thought that I escaped.

So it took a while from here, where I just searched around, and did my stuff. I then noticed that I didn't have SCP-1499, and thought that I didn't get it, so I decided to go back. When I then returned to where SCP-1499 was, I could hear the sounds that plays when SCP-106 is nearby.
I didn't pay attention, so I just opened the keycard door to SCP-1499, and what I saw, scared the living hell out of me. I saw SCP-106 in the room, right at the door entrance, and I quickly ran away again. But I noticed that the sound disappeared, so I returned. When I got back, I saw that SCP-106 was trying to go through the open Keycard door, but apparently, there's an invisible wall for him. So basically, right now, while I'm staring at him, he's doing moonwalks, without moving forward, or backward. Just sliding left and right, as I move around at the other side. I even tried to go far far away from SCP-106, but when I returned, he was still having trouble getting through that wide-open door.
I then saved, and reloaded, and found SCP-106 halfway through the floor, just standing there.
I then walked into him and... surprisingly.. nothing happened.. At all. Well. Apart from me bumping into him, and having to go around.
I then went into the room where SCP-1499 was supposed to be lying, but it wasn't there.
I guess, no SCP-1499 for me..
So now I'm just standing in that room, staring at SCP-106. I even got the message "STOP HIDING!" And got startled.
Either way. Hope this was helpful in any way.
I guess I'll have to start a new game, if I want SCP-1499, without using the Console, and still want to be chased by SCP-106.

This was during the release of SCP:CB v1.3.9

It happened to me too when i was escaping and i went to 1499 scp room to hide from him