How to join the TTN platform in China in China recently?

I deployed the lorawan network in China, but I encountered some problems when joining the TTN platform. The problems are as follows:
First, by joining the network through ABP, the node module can upload data to the TTN platform, but the data issued by the TTN platform cannot be received by the node module.
Second, the node module cannot always join the TTN platform through the OTAA mode.
Third, a few months ago I used the same node module and gateway for debugging. No matter it is ABP or OTAA mode, it can upload and send data.

You apparently have a downlink issue.

Without providing any details about your gateway, node, hardware, software, configuration settings, tests performed etc. it will be very dificult for others to provide any help.

If you are familiar with debugging then you also know that you need to provide details about your situation when asking for help.

Data in OTAA mode:

image

image

Data in ABP mode:

image

image

I guess my frequency plan is wrong, it doesn’t match the TTN platform.

My uplink frequency is:

1.486.3-SF7BW125 to SF12BW125
2.486.5-SF7BW125 to SF12BW125
3.486.7-SF7BW125 to SF12BW125
4.486.9-SF7BW125 to SF12BW125
5.487.1-SF7BW125 to SF12BW125
6.487.3-SF7BW125 to SF12BW125
7.487.5-SF7BW125 to SF12BW125
8.487.7-SF7BW125 to SF12BW125

The downlink frequency is:

1.506.7-SF7BW125 to SF12BW125
2.506.9-SF7BW125 to SF12BW125
3.507.1-SF7BW125 to SF12BW125
4.507.3-SF7BW125 to SF12BW125
5.507.5-SF7BW125 to SF12BW125
6.507.7-SF7BW125 to SF12BW125
7.507.9-SF7BW125 to SF12BW125
8.508.1-SF7BW125 to SF12BW125
9.505.3-SF12BW125 (RX2 only downlink)

What gateway are you using and what node?
What software are you running on the node?
How are the node and gateway configured?

I have no experience whith ISM band and frequencies that are used for TTN in China.
But the frequency plans have to be set correctly for your location.

The gateways and nodes are made by Chinese domestic manufacturers. A few months ago, the uplink data and downlink data were normal, but it has been abnormal since March. I wonder if any changes have been made to the TTN platform.