OpenVPN Connection stuck at TLS Initial packet

OpenVPN suddenly stopped connecting from the AX-1800 to my OpenVPN server hosted on an AWS Lightsail instance.

It fails at the TLS Initial packet step, please find the complete log below (I've replaced the OpenVPN server's IP with AWS_INSTANCE_IP in the logs):

Sat Jun  1 15:54:41 2024 daemon.notice netifd: Interface 'ovpnclient' is setting up now
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: OpenVPN 2.5.3 arm-openwrt-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [MH/PKTINFO] [AEAD]
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: library versions: OpenSSL 1.1.1l  24 Aug 2021, LZO 2.10
Sat Jun  1 15:54:43 2024 daemon.warn ovpnclient[17833]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: Outgoing Control Channel Encryption: Cipher 'AES-256-CTR' initialized with 256 bit key
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: Outgoing Control Channel Encryption: Using 256 bit message hash 'SHA256' for HMAC authentication
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: Incoming Control Channel Encryption: Cipher 'AES-256-CTR' initialized with 256 bit key
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: Incoming Control Channel Encryption: Using 256 bit message hash 'SHA256' for HMAC authentication
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: TCP/UDP: Preserving recently used remote address: [AF_INET]AWS_INSTANCE_IP:443
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: Socket Buffers: R=[87380->87380] S=[16384->16384]
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: Attempting to establish TCP connection with [AF_INET]AWS_INSTANCE_IP:443 [nonblock]
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: TCP connection established with [AF_INET]AWS_INSTANCE_IP:443
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: TCP_CLIENT link local: (not bound)
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: TCP_CLIENT link remote: [AF_INET]AWS_INSTANCE_IP:443
Sat Jun  1 15:54:43 2024 daemon.notice ovpnclient[17833]: TLS: Initial packet from [AF_INET]AWS_INSTANCE_IP:443, sid=bf239ef6 4c7d93bc

To make sure it's not an ISP/DPI issue, I tested the same OpenVPN config on my PC and mobile phone, and they are both connecting normally.

Your support is highly appreciated, thanks!

Edit: Additional Info:
I've tried resetting the router, upgrading to the latest BETA and Snapshot versions, and the issue is still there.
I used to connect normally using the same config, so I can't wrap my head around what exactly changed.

Without that you changed anything? Not on your router nor on the AWS instance or any other things?

Nope, nothing at all.

I assume the issue is with the server, not the client.
Unfortunately I can't tell which issue it might be.

Thanks for your input on this.

Do you suggest a specific configuration to check on the server?

TBH I am doubting it's the server since my PC and Mobile can connect normally to the same server using the same config.

Pls post the ovpn content to have a check.

Sorry about the late response, please find below:

client
dev tun
proto tcp
remote {IP ADDRESS} 443
resolv-retry infinite
nobind
remote-cert-tls server
tls-version-min 1.2
verify-x509-name ip-172-26-12-18_34bbb216-3a9e-4092-8a9f-aa06d1144e21 name
cipher AES-256-CBC
auth SHA256
auth-nocache
verb 3
<ca>
-----BEGIN CERTIFICATE-----
{CERTIFICATE}
-----END CERTIFICATE-----
</ca>
<cert>
-----BEGIN CERTIFICATE-----
{CERTIFICATE}
-----END CERTIFICATE-----
</cert>
<key>
-----BEGIN PRIVATE KEY-----
{PRIVATE_KEY}
-----END PRIVATE KEY-----
</key>
<tls-crypt>
#
# 2048 bit OpenVPN static key
#
-----BEGIN OpenVPN Static key V1-----
{STATIC_KEY}
-----END OpenVPN Static key V1-----
</tls-crypt>