diff --git a/phpstan.neon b/phpstan.neon
index b67c8d47..75da21cf 100644
--- a/phpstan.neon
+++ b/phpstan.neon
@@ -2782,7 +2782,7 @@ parameters:
 
         -
             message: "#^Parameter \\#1 \\$haystack of function stripos expects string, mixed given\\.$#"
-            count: 5
+            count: 4
             path: src/Invoice/Renderer/AbstractSpreadsheetRenderer.php
 
         -
diff --git a/src/Export/Package/SpoutSpreadsheet.php b/src/Export/Package/SpoutSpreadsheet.php
index 014c5fd9..94382bde 100644
--- a/src/Export/Package/SpoutSpreadsheet.php
+++ b/src/Export/Package/SpoutSpreadsheet.php
@@ -11,6 +11,7 @@ namespace App\Export\Package;
 
 use App\Constants;
 use OpenSpout\Common\Entity\Cell;
+use OpenSpout\Common\Entity\Cell\StringCell;
 use OpenSpout\Common\Entity\Row;
 use OpenSpout\Common\Entity\Style\Border;
 use OpenSpout\Common\Entity\Style\BorderPart;
@@ -98,7 +99,8 @@ class SpoutSpreadsheet implements SpreadsheetPackage
         $style->setShouldWrapText(false);
         $style->setShouldShrinkToFit(true);
 
-        if (\array_key_exists('totals', $options) && $options['totals'] === true) {
+        $isTotalsRow = \array_key_exists('totals', $options) && $options['totals'] === true;
+        if ($isTotalsRow) {
             if ($this->writer instanceof CSVWriter) {
                 return;
             }
@@ -109,7 +111,11 @@ class SpoutSpreadsheet implements SpreadsheetPackage
         $tmp = [];
         $i = 0;
         foreach ($columns as $column) {
-            $tmp[] = Cell::fromValue($column, $this->styles[$i++]); // @phpstan-ignore argument.type
+            if (!$isTotalsRow && \is_string($column)) {
+                $tmp[] = new StringCell($column, $style);
+            } else {
+                $tmp[] = Cell::fromValue($column, $this->styles[$i++]); // @phpstan-ignore argument.type
+            }
         }
 
         $this->writer->addRow(new Row($tmp, $style));
diff --git a/src/Invoice/Renderer/AbstractSpreadsheetRenderer.php b/src/Invoice/Renderer/AbstractSpreadsheetRenderer.php
index 78401369..8edd42dd 100644
--- a/src/Invoice/Renderer/AbstractSpreadsheetRenderer.php
+++ b/src/Invoice/Renderer/AbstractSpreadsheetRenderer.php
@@ -67,10 +67,6 @@ abstract class AbstractSpreadsheetRenderer extends AbstractRenderer
                     continue;
                 }
                 $replacer = null;
-                $firstReplacerPos = stripos($value, '${');
-                if ($firstReplacerPos === false) {
-                    continue;
-                }
 
                 if (stripos($value, '${entry.') !== false) {
                     if ($sheetValues === false && isset($entries[$entryRow])) {
@@ -94,13 +90,14 @@ abstract class AbstractSpreadsheetRenderer extends AbstractRenderer
                     if (stripos($value, $searchKey) === false) {
                         continue;
                     }
-                    if (\is_string($content) && str_starts_with($content, '=')) {
+                    // we ONLY check if the given replacer content contains a formula character
+                    if (\is_string($content) && \in_array($content[0], ['=', '-', '+', '@', "\t", "\r"])) {
                         $contentLooksLikeFormula = true;
                     }
                     $value = str_replace($searchKey, $content ?? '', $value);
                 }
 
-                if ($contentLooksLikeFormula && $firstReplacerPos === 0) {
+                if ($contentLooksLikeFormula) {
                     // see https://github.com/kimai/kimai/pull/2054
                     $cell->setValueExplicit($value, DataType::TYPE_STRING);
                 } else {