IRC to Matrix: cannot create filters for others users

[MyWay]

Describe the bug
The bridge is running, I'm getting a lot of these messages though:
msg=Failed to POST JSON to /_matrix/client/r0/user/@myUser:matrix.org/filter code=403 wrapped=M_FORBIDDEN: Cannot create filters for other users
IRC -> Matrix messages are relayed
Matrix -> IRC are not

To Reproduce
No idea, I'm coming from a very old matterbridge version and just updated to latest stable, if this helps.

Expected behavior
I'd expect to not have this error and if related, to relay messages IRC <-> Matrix correctly.

Environment (please complete the following information):

• OS: Linux
• Matterbridge version: latest stable

Additional context

[matrix]
[matrix.mychanname]
Server="https://matrix.org"
MxID="@myid:matrix.org"
Token=""
Login="mylogin"
Password="mypassword"
NoHomeServerSuffix=true
UseUserName=false
IgnoreMessages="^~~ badword"
ShowJoinPart=false
ShowTopicChange=false
HTMLDisable=true

[general]
RemoteNickFormat="<{NICK}> "

[irc]
[irc.mychanname]
Server="myserverhostname:6697"
Nick="mynick"
UseTLS=true
SkipTLSVerify=true
UseSASL=true
NickServNick="mynick"
NickServPassword="mypassword"
#Flood control
#Delay in milliseconds between each message send to the IRC server
#OPTIONAL (default 1300)
MessageDelay=50
#Maximum amount of messages to hold in queue. If queue is full 
#messages will be dropped. 
#<message clipped> will be add to the message that fills the queue.
#OPTIONAL (default 30)
MessageQueue=50
#Maximum length of message sent to irc server. If it exceeds
#<message clipped> will be add to the message.
#OPTIONAL (default 400)
MessageLength=256
#Nicks you want to ignore. 
#Messages from those users will not be sent to other bridges.
#OPTIONAL
IgnoreNicks="ircspammer1 ircspammer2"
#Messages you want to ignore. 
#Messages matching these regexp will be ignored and not sent to other bridges
#See https://regex-golang.appspot.com/assets/html/index.html for more regex info
#OPTIONAL (example below ignores messages starting with ~~ or messages containing badword
IgnoreMessages="^~~ badword"
#RemoteNickFormat defines how remote users appear on this bridge 
#The string "{NICK}" (case sensitive) will be replaced by the actual nick / username.
#The string "{BRIDGE}" (case sensitive) will be replaced by the sending bridge
#The string "{PROTOCOL}" (case sensitive) will be replaced by the protocol used by the bridge
#The string "{NOPINGNICK}" (case sensitive) will be replaced by the actual nick / username, but with a ZWSP inside the nick, so the irc user with the same nick won't get pinged. See https://github.com/4$
#Enable to show users joins/parts from other bridges 
#Only works hiding/show messages from irc and mattermost bridge for now
#OPTIONAL (default false)
ShowJoinPart=false
#StripNick only allows alphanumerical nicks. See https://github.com/42wim/matterbridge/issues/285
#It will strip other characters from the nick
#OPTIONAL (default false)
StripNick=false
Charset="utf8"
UserName="myusername"
RealName="myrealname"
MessageClipped="<clipped message>"

[[gateway]]
    name = "mygateway"
    enable=true

[[gateway.inout]]
account = "irc.mychanname"
channel = "#mychanname"
[gateway.inout.options]
key = "myircchankey"

[[gateway.inout]]
account ="matrix.mychanname"
channel = "#myotherchanname:matrix.org"

[MyWay]

That was due to a wrong mxid.