ESP8266 Unable to Connect to Two WebSocket Servers Simultaneously Using arduinoWebSockets

I'm trying to use an ESP8266 to connect to two WebSocket servers simultaneously using the arduinoWebSockets library. This is a snippet of my code. I then attempt to display data on 7 segment displays.

#include <WebSocketsClient.h>

WebSocketsClient flightWebSocket;
WebSocketsClient cryptoWebSocket;

void setup() {
  // Setup WebSocket 1 (Flight Data)
  flightWebSocket.beginSSL("****", 443, "/api/ws", NULL, "");

  delay(100);

  // Setup WebSocket 2 (Crypto Data)
  cryptoWebSocket.beginSSL("****", 443, "/prices?assets=bitcoin", NULL, "");

  // Enable heartbeat for both WebSockets
  flightWebSocket.enableHeartbeat(50000, 5000, 0);
  cryptoWebSocket.enableHeartbeat(50000, 5000, 0);

  // Set reconnect intervals
  flightWebSocket.setReconnectInterval(4000);
  cryptoWebSocket.setReconnectInterval(4000);
}

void loop() {
  // Call loop for both WebSockets
  flightWebSocket.loop();
  cryptoWebSocket.loop();
}

Here's the issue:

One WebSocket stays connected, but the second fails to connect repeatedly. When I try the same code on an ESP32, it works perfectly fine. But I would prefer to use a ESP8266 Question Is this issue caused by:

A limitation of the ESP8266 hardware? A limitation in the arduinoWebSockets library's implementation for the ESP8266? Or is there something else I might be overlooking?