set implicit params with extra SPI call where required

src/modules/SX126x/SX126x.cpp

@@ -290,6 +290,14 @@ int16_t SX126x::receive(uint8_t* data, size_t len) {
     float symbolLength = (float)(uint32_t(1) << _sf) / (float)_bwKhz;
     timeout = (uint32_t)(symbolLength * 100.0 * 1000.0);
 
+      // set implicit mode and expected len if applicable
+      if (_headerType == SX126X_LORA_HEADER_IMPLICIT) {
+          state = setPacketParams(_preambleLength, _crcType, _implicitLen, _headerType);
+          if(state != ERR_NONE) {
+            return(state);
+          }
+      }
+
   } else if(modem == SX126X_PACKET_TYPE_GFSK) {
     // calculate timeout (500 % of expected time-one-air)
     size_t maxLen = len;
@@ -600,6 +608,14 @@ int16_t SX126x::startReceiveCommon() {
   // clear interrupt flags
   state = clearIrqStatus();
 
+  // set implicit mode and expected len if applicable
+  if (_headerType == SX126X_LORA_HEADER_IMPLICIT && getPacketType() == SX126X_PACKET_TYPE_LORA) {
+      state = setPacketParams(_preambleLength, _crcType, _implicitLen, _headerType);
+      if(state != ERR_NONE) {
+        return(state);
+      }
+  }
+
   return(state);
 }